Cut-off, Black Smoke
09-30-2002, 08:19 PM
#1
Addict
Rennlist Member
Rennlist Member
Thread Starter
Cut-off, Black Smoke
Hi Everyone
I was taken on yesterday by a hotted up Honda Integra...
In the dice from the lights I managed to get the thing to cut-off, and when I looked back my car had blown some black smoke.
Have I done real damage?
Engine sounds fine (in fact it seemed to go better afterwards
)
BTW - I left him standing.... <img src="graemlins/bigok.gif" border="0" alt="[thumbsup]" />
I was taken on yesterday by a hotted up Honda Integra...
In the dice from the lights I managed to get the thing to cut-off, and when I looked back my car had blown some black smoke.
Have I done real damage?
Engine sounds fine (in fact it seemed to go better afterwards
)BTW - I left him standing.... <img src="graemlins/bigok.gif" border="0" alt="[thumbsup]" />
09-30-2002, 09:41 PM
#2
Addict
Rennlist
Lifetime Member
Rennlist
Lifetime Member
Kevin,
Do you mean you redlined the car and hit the cut off of the fuel?
Was your car up to temperature?
There was a post with the same question on the 911 or 964 board. Adrian said that it was nothing to worry about.
Regards,
Sonny
ps: Good kill... should be no problem. I have an '94 Integra GSR as a daily driver. The low end torque is very sad.
Do you mean you redlined the car and hit the cut off of the fuel?
Was your car up to temperature?
There was a post with the same question on the 911 or 964 board. Adrian said that it was nothing to worry about.
Regards,
Sonny
ps: Good kill... should be no problem. I have an '94 Integra GSR as a daily driver. The low end torque is very sad.
10-01-2002, 03:49 AM
#3
Addict
Rennlist Member
Rennlist Member
Thread Starter
Sonny,
Thanks, I think I do remember that thread. I don't think it has done the engine any real harm, but I do notice a much more prominent hissing under boost. I suspect my boost hose or something has a problem...
Any thoughts....
Thanks, I think I do remember that thread. I don't think it has done the engine any real harm, but I do notice a much more prominent hissing under boost. I suspect my boost hose or something has a problem...
Any thoughts....
10-01-2002, 06:15 AM
#4
Burning Brakes
Join Date: Jun 2001
Location: Stockholm, Sweden
Posts: 1,232
Likes: 0
Received 0 Likes
on
0 Posts
Blue and white smoke should make you "really worried", black smoke means less worried but you should check things to make sure.
If the cut-off was VERY violent, Sonny can describe the feeling, "teeth marks on the steering wheel kind of thing", then you have a overboost situation that needs to be taken care of ASAP.
The hissing sound could be a leak and the pressure hose between the intercooler and the turbo is probably one of your prime suspects.
I would start by checking this hose.
Have you removed your intercooler lately ?
Have someone drive behind the car (engine warm) and have them check if there is any smoke, what color of smoke and what pipe it's coming from.
Do this test accelerating hard but also when downshifting. The biggest problem is probably to find someone that have a fast enough car :-)
With this test you have more information which is probably what you need right now, for peace of mind or trouble shooting.
I could also be that you redlined the car, had the cut-off got worried and hear things that was there all along. You wouldn't be the first...
Staffan
If the cut-off was VERY violent, Sonny can describe the feeling, "teeth marks on the steering wheel kind of thing", then you have a overboost situation that needs to be taken care of ASAP.
The hissing sound could be a leak and the pressure hose between the intercooler and the turbo is probably one of your prime suspects.
I would start by checking this hose.
Have you removed your intercooler lately ?
Have someone drive behind the car (engine warm) and have them check if there is any smoke, what color of smoke and what pipe it's coming from.
Do this test accelerating hard but also when downshifting. The biggest problem is probably to find someone that have a fast enough car :-)
With this test you have more information which is probably what you need right now, for peace of mind or trouble shooting.
I could also be that you redlined the car, had the cut-off got worried and hear things that was there all along. You wouldn't be the first...
Staffan
10-01-2002, 07:56 AM
#5
Addict
Lead Rennlist
Technical Advisor
Rennlist
Lifetime Member
Lead Rennlist
Technical Advisor
Rennlist
Lifetime Member
Dear Sonny,
It is no problem on a normally aspirated 964 because the fuel is not cut off it is a rpm governor. However this cannot be translated across to the 964 Turbos. The Turbos have a fuel cut off which is far more dramatic.
I would not take any major notice of smoke blowing when this occurs but certainly anything afterwards would certainly get my attention. Hissing noises which suggest a blown off pipe, burst pipe or stuck valve would certainly have my full attention.
Hitting redline also helps blow out the cobwebs so in itself it is not a bad thing. Please remember these are sports cars and are not made from glass. They are not fragile.
Ciao,
Adrian
911C4
PS: There was a great show on tv here a few months back showing tests carried out on Porsche, Ferrari and Lambo. The tests were to destruction. What a job! as the Ferrari guy says, he has the best job in the world. Taking a Ferrari to its limit and beyond and not getting into trouble for it.
It is no problem on a normally aspirated 964 because the fuel is not cut off it is a rpm governor. However this cannot be translated across to the 964 Turbos. The Turbos have a fuel cut off which is far more dramatic.
I would not take any major notice of smoke blowing when this occurs but certainly anything afterwards would certainly get my attention. Hissing noises which suggest a blown off pipe, burst pipe or stuck valve would certainly have my full attention.
Hitting redline also helps blow out the cobwebs so in itself it is not a bad thing. Please remember these are sports cars and are not made from glass. They are not fragile.
Ciao,
Adrian
911C4
PS: There was a great show on tv here a few months back showing tests carried out on Porsche, Ferrari and Lambo. The tests were to destruction. What a job! as the Ferrari guy says, he has the best job in the world. Taking a Ferrari to its limit and beyond and not getting into trouble for it.
10-01-2002, 02:51 PM
#6
Racer
Join Date: Jan 2002
Location: UK
Posts: 415
Likes: 0
Received 0 Likes
on
0 Posts
I've hit the rev limiter a few times and not noticed any unpleasant side effects. In fact I think it did, as Adrian suggests, clear out the cobwebs and cure a fast idle problem the car had picked up sittig in the garage.
BTW Adrian - you're right, what a job! What sort of things did they have to do to break the cars??
BTW Adrian - you're right, what a job! What sort of things did they have to do to break the cars??
10-01-2002, 08:01 PM
#7
Addict
Rennlist Member
Rennlist Member
Thread Starter
Thanks for the posts everyone....
Here's an update!
That hissing sound must have been serious - car wouldn't start last night
Anyway, got it to Porsche, and we think it is one of the hoses come loose or burst.
While they are at it, I asked them to check and replace if nec. the CBV. I have a feeling this was on its was out too because the 'pssst' has diminished over time when one lifts off the pedal under boost. Performance has also been deteriorating.
There are a couple of other niggles, like the passenger door (driver door to those who drive on the wrong side of the road ) is out of line... it scrapes on the engine lid latch. There are a couple of other things, nothing serious...
Anyhow - probably good to give it a once over now and get things right.
Now, this has me thinking...here's why:
I had this same problem when I first picked up the car. I drove it really hard (no red line cut off tho'), and after a month there was this loud hissing when accelerating, which got worse under boost. It turned out to be a boost hose. This was fixed, car's been great. It is now a couple of months later, same problem. So. Does this mean that the hoses cannot keep up with the boost of the engine? (Admittedly, I have done a track day since they were last fixed)... but still, seems weird that Porsche didn't design in more strength than necessary.... they overengineer so much else?
Thoughts?
<img src="confused.gif" border="0">
Here's an update!
That hissing sound must have been serious - car wouldn't start last night
Anyway, got it to Porsche, and we think it is one of the hoses come loose or burst.
While they are at it, I asked them to check and replace if nec. the CBV. I have a feeling this was on its was out too because the 'pssst' has diminished over time when one lifts off the pedal under boost. Performance has also been deteriorating.
There are a couple of other niggles, like the passenger door (driver door to those who drive on the wrong side of the road
) is out of line... it scrapes on the engine lid latch. There are a couple of other things, nothing serious...Anyhow - probably good to give it a once over now and get things right.
Now, this has me thinking...here's why:
I had this same problem when I first picked up the car. I drove it really hard (no red line cut off tho'), and after a month there was this loud hissing when accelerating, which got worse under boost. It turned out to be a boost hose. This was fixed, car's been great. It is now a couple of months later, same problem. So. Does this mean that the hoses cannot keep up with the boost of the engine? (Admittedly, I have done a track day since they were last fixed)... but still, seems weird that Porsche didn't design in more strength than necessary.... they overengineer so much else?
Thoughts?
<img src="confused.gif" border="0">
Trending Topics
10-02-2002, 05:58 AM
#8
Addict
Lead Rennlist
Technical Advisor
Rennlist
Lifetime Member
Lead Rennlist
Technical Advisor
Rennlist
Lifetime Member
Dear Greg,
It is hard to explain what they did because they did many things to many different autos to get things to fail. Destroying the engine and suspension required foot flat to the floor in 1st gear whilst doing donuts. They keep a record of how many complete circles they make before the engine lets go. Things like that. Changing from top to first whilst going flat out and timing how long it takes to explode.
Dear Kevin,
Based on personal experience with other European autos in Australia I believe the problem may be the local environment as well, especially on hoses. The other issue is that sports car do need to be driven in the way that they were designed to be used. High speed autobahn driving is required. Constant puttering around in city traffic causes excessive build up of heat and damages the items like hoses.
Also remember that even synthetic rubber has a life limit. When you purchase a spare hose you will often never know how old it is nor the conditions under which it was stored. Incorrect storage temperature and humidity levels play a signifcant role in reducing the life of such items. Some of these spares may well be 10 years old before you purchase them.
Ciao,
Adrian
911C4
It is hard to explain what they did because they did many things to many different autos to get things to fail. Destroying the engine and suspension required foot flat to the floor in 1st gear whilst doing donuts. They keep a record of how many complete circles they make before the engine lets go. Things like that. Changing from top to first whilst going flat out and timing how long it takes to explode.
Dear Kevin,
Based on personal experience with other European autos in Australia I believe the problem may be the local environment as well, especially on hoses. The other issue is that sports car do need to be driven in the way that they were designed to be used. High speed autobahn driving is required. Constant puttering around in city traffic causes excessive build up of heat and damages the items like hoses.
Also remember that even synthetic rubber has a life limit. When you purchase a spare hose you will often never know how old it is nor the conditions under which it was stored. Incorrect storage temperature and humidity levels play a signifcant role in reducing the life of such items. Some of these spares may well be 10 years old before you purchase them.
Ciao,
Adrian
911C4
10-02-2002, 07:41 AM
#9
Intermediate
Join Date: Sep 2002
Location: Sydney, Australia
Posts: 27
Likes: 0
Received 0 Likes
on
0 Posts
Hi Kevin,
I can't believe you took on a Honda Integra, why bother? My appologies to the Integra owner, I don't mean to appear arrogant, but we all know the 0-100 times of a Porsche turbo so if the car edging you on does not even come close, I just look the other way.
Revving the Porsche to the red-line is something it was engineered to do, just about all day so I would not be too concerned. I have taken mine to the red line fuel cutoff limit in second gear, which equates to about 120kmh and yes it cuts out with a vengence at the redline! and just to scare you even further makes a horrible chuff sound.
The other day, I decided to take mine on the expressway for a fast run. This car has never seen the expressway before, so I took it easy so as not to scare it! Basically in 4th all the way up to about 200kmh, then back down to 100kmh and up to 5th for a while to lower the revs. Repeated a couple of times and then returned home.
The car now idles better from cold, and generally feels smoother. I mean this is not rocket science as already mentioned by the other members, these cars hate constant city driving.
Problem is the police and speed cameras, which make it difficult to open her up too often, I was lucky this time round.
So Kevin if you car is not blowing smoke during normal driving there is nothing to be concerned about.
I aggree with the comment re hoses aging and damaging with heat. When the car is in motion, cool air is being sucked in through the tail slots which cools the top part of the engine compartment before being again sucked into the fan to cool the cylinders...the important parts!
When the car is parked, there is an enormous amount of heat being generated by the hot engine, and rises up into the engine area heating up hoses, electronics, and everything else in there.
Eventually the hot air escapes up through the tail. You can check this out yourself by driving the car, then stop, park the car and put your hand on the tail air intake slots, the area is cool. Open the tail and notice the temperature inside the engine compartment. Now wait 10 mins and feel the tail area again, this time it is stinking hot!
So what to do? Easy, when I park the car in my garage, I lay a piece of carpet which covers all the slots on the tail area. In the middle of the carpet I cut a hole about 12 ins in diameter, on top of which I rest a blower fan, those used in toilets etc. This forces cool air down into the engine compartment, through the fan and past the cylinders.
Thus stopping all that heat from soaking the engine compartment. You should feel the heat comming out through the wheels and under the engine area. The fan is left on for about 2 hours, by which time the engine is nice and cool.
I love it! It like the car is still being cooled without moving or the engine operating. Total cost, a piece of carpet and an old 240V toilet blower.
By for now.
Peter
964 Turbo 3.6
I can't believe you took on a Honda Integra, why bother? My appologies to the Integra owner, I don't mean to appear arrogant, but we all know the 0-100 times of a Porsche turbo so if the car edging you on does not even come close, I just look the other way.
Revving the Porsche to the red-line is something it was engineered to do, just about all day so I would not be too concerned. I have taken mine to the red line fuel cutoff limit in second gear, which equates to about 120kmh and yes it cuts out with a vengence at the redline! and just to scare you even further makes a horrible chuff sound.
The other day, I decided to take mine on the expressway for a fast run. This car has never seen the expressway before, so I took it easy so as not to scare it! Basically in 4th all the way up to about 200kmh, then back down to 100kmh and up to 5th for a while to lower the revs. Repeated a couple of times and then returned home.
The car now idles better from cold, and generally feels smoother. I mean this is not rocket science as already mentioned by the other members, these cars hate constant city driving.
Problem is the police and speed cameras, which make it difficult to open her up too often, I was lucky this time round.
So Kevin if you car is not blowing smoke during normal driving there is nothing to be concerned about.
I aggree with the comment re hoses aging and damaging with heat. When the car is in motion, cool air is being sucked in through the tail slots which cools the top part of the engine compartment before being again sucked into the fan to cool the cylinders...the important parts!
When the car is parked, there is an enormous amount of heat being generated by the hot engine, and rises up into the engine area heating up hoses, electronics, and everything else in there.
Eventually the hot air escapes up through the tail. You can check this out yourself by driving the car, then stop, park the car and put your hand on the tail air intake slots, the area is cool. Open the tail and notice the temperature inside the engine compartment. Now wait 10 mins and feel the tail area again, this time it is stinking hot!
So what to do? Easy, when I park the car in my garage, I lay a piece of carpet which covers all the slots on the tail area. In the middle of the carpet I cut a hole about 12 ins in diameter, on top of which I rest a blower fan, those used in toilets etc. This forces cool air down into the engine compartment, through the fan and past the cylinders.
Thus stopping all that heat from soaking the engine compartment. You should feel the heat comming out through the wheels and under the engine area. The fan is left on for about 2 hours, by which time the engine is nice and cool.
I love it! It like the car is still being cooled without moving or the engine operating. Total cost, a piece of carpet and an old 240V toilet blower.
By for now.
Peter
964 Turbo 3.6
10-02-2002, 10:37 PM
#11
Rennlist Member
Alternatively, you could find a couple of feline heat sinks.
The moggy pictured here was continually trying to sleep on the tail, and got sick of being moved off [cat hair all over the place] so he decided to try the wing over the oil cooler instead. The problem with that is that he put his claws out instinctively when he started to slide off and scratched the side
36 sleeps until I'm back in the driver seat. Sounds like I've got plenty of noises to listen out for!
The moggy pictured here was continually trying to sleep on the tail, and got sick of being moved off [cat hair all over the place] so he decided to try the wing over the oil cooler instead. The problem with that is that he put his claws out instinctively when he started to slide off and scratched the side
36 sleeps until I'm back in the driver seat. Sounds like I've got plenty of noises to listen out for!
10-03-2002, 03:20 AM
#12
Drifting
The way the intercooler sits on the throttle body is quite cheesy. There is an o-ring (orange) that sits in a slot and the intercooler is placed on top of the throttle body and over the o-ring on the TB. This o-ring blows out quite easily if you are running a lot of boost or if the intercooler is not installed correctly.
It takes two people to tighten the two side bolts on the IC. One to hold the IC in place and one to tighten the bolts. Most shops don't have the time to have two guys putting on an IC so they plop the IC onto the TB and it all looks great. They start tightening the bolts and it moves up a bit. They take it for a test drive, everything is fine. The first time you get on it hard, it blows the o-ring out and you are left with a car that won't even start.
fc-racer
It takes two people to tighten the two side bolts on the IC. One to hold the IC in place and one to tighten the bolts. Most shops don't have the time to have two guys putting on an IC so they plop the IC onto the TB and it all looks great. They start tightening the bolts and it moves up a bit. They take it for a test drive, everything is fine. The first time you get on it hard, it blows the o-ring out and you are left with a car that won't even start.
fc-racer
10-04-2002, 10:28 AM
#13
Addict
Rennlist Member
Rennlist Member
Thread Starter
fc-racer
I got my car back last night, and they said it was a hose that was loose on the inlet manifold (?) - kinda sounds like you are spot on!
BTW - they checked the CBV, and it was good. So I am trying to nail still why the power seems to be somewhat off. Even with the hose fixed, the car seems ... without , ummm, the word.... ah, fury! It is still very quick, but it just doesn't seem furious.
Any ideas?
BTW- looked at your pics. V-e-r-y N-i-c-e!!! Those wheels really do the job! Is it lowered? or is it the 18' rims?
Bye For Now <img src="graemlins/xyxwave.gif" border="0" alt="[bigbye]" />
I got my car back last night, and they said it was a hose that was loose on the inlet manifold (?) - kinda sounds like you are spot on!
BTW - they checked the CBV, and it was good. So I am trying to nail still why the power seems to be somewhat off. Even with the hose fixed, the car seems ... without , ummm, the word.... ah, fury! It is still very quick, but it just doesn't seem furious.
Any ideas?
BTW- looked at your pics. V-e-r-y N-i-c-e!!! Those wheels really do the job! Is it lowered? or is it the 18' rims?
Bye For Now <img src="graemlins/xyxwave.gif" border="0" alt="[bigbye]" />
10-04-2002, 12:56 PM
#14
Racer
Join Date: Jan 2002
Location: UK
Posts: 415
Likes: 0
Received 0 Likes
on
0 Posts
Kevin -
In my earlier post I should have said "I've redlined it without feeing unpleasant side effects" - until today I hadn't actually hit the limiter.
So just out of interest when I took my car out today I let the revs hit the limiter - it cut off so violently I nearly bit the end of my tongue off!!
I can see why you were concerned it might have caused damage.
PS - I also had the fast idle problem again - when I start the car up it idles at around 2K rpm instead of 800 - and then gradually rises to 2500rpm. The only way to get rid of it is to rev the car hard - this time I only tried revving it hard once or twice - no more - and that made it settle down.
Weird. That's twice in a row I've had the fast idle problem. It doesn't go away just through restarting, through warming up, or through disconnecting the battery. But as soon as I take it to the redline, even just once or twice - it settles down. Switch the car off, wait 15 minutes - and the idle speed has risen again to 1,500 rpm.
Anyone guess what's going on here?? <img src="confused.gif" border="0">
In my earlier post I should have said "I've redlined it without feeing unpleasant side effects" - until today I hadn't actually hit the limiter.
So just out of interest when I took my car out today I let the revs hit the limiter - it cut off so violently I nearly bit the end of my tongue off!!
I can see why you were concerned it might have caused damage.
PS - I also had the fast idle problem again - when I start the car up it idles at around 2K rpm instead of 800 - and then gradually rises to 2500rpm. The only way to get rid of it is to rev the car hard - this time I only tried revving it hard once or twice - no more - and that made it settle down.
Weird. That's twice in a row I've had the fast idle problem. It doesn't go away just through restarting, through warming up, or through disconnecting the battery. But as soon as I take it to the redline, even just once or twice - it settles down. Switch the car off, wait 15 minutes - and the idle speed has risen again to 1,500 rpm.
Anyone guess what's going on here?? <img src="confused.gif" border="0">
10-05-2002, 03:28 AM
#15
Drifting
[quote]Originally posted by Kevin Ross:
<strong>fc-racer
I got my car back last night, and they said it was a hose that was loose on the inlet manifold (?) - kinda sounds like you are spot on!
BTW - they checked the CBV, and it was good. So I am trying to nail still why the power seems to be somewhat off. Even with the hose fixed, the car seems ... without , ummm, the word.... ah, fury! It is still very quick, but it just doesn't seem furious.
Any ideas?
BTW- looked at your pics. V-e-r-y N-i-c-e!!! Those wheels really do the job! Is it lowered? or is it the 18' rims?
Bye For Now <img src="graemlins/xyxwave.gif" border="0" alt="[bigbye]" /> </strong><hr></blockquote>
If the power output feels low, there are only three things that can be wrong:
1. Boost is too low (wastegate problem)
2. Not enough air is getting into the engine (induction leak)
3. Fuel is not reaching the engine (fuel filter, fuel pump, etc.)
#3 will add other driveability problems so I think we can rule that one out. #1 should be easy to test with a simple boost gauge tapped into your CBV vacuum hose.
#2 is most likely. More than likely, your CBV is torn and leaking boost back into the non-pressurized side of the intake. Even though these test ok, they are known to fail, it's not a matter of if, but when. You should at the very least replace it with a 993 valve or better yet, replace it with a Forge or Baileys valve. I use a Forge valve and notice a big difference in performance from the 993 valve, especially on the fast shifts, it holds boost much better. With the higher boost I run, it makes an even bigger difference.
So, first, replace the CBV even if the shop says it's good. Second, check your boost pressure and report back.
Thanks for the compliments. The wheels are 18" from a 993 and the car is lowered using a RUF suspension. The combo works quite well on the street and track.
I finally got the 2pc 3.8RS splitter in, will get that installed soon.
fc-racer
<strong>fc-racer
I got my car back last night, and they said it was a hose that was loose on the inlet manifold (?) - kinda sounds like you are spot on!
BTW - they checked the CBV, and it was good. So I am trying to nail still why the power seems to be somewhat off. Even with the hose fixed, the car seems ... without , ummm, the word.... ah, fury! It is still very quick, but it just doesn't seem furious.
Any ideas?
BTW- looked at your pics. V-e-r-y N-i-c-e!!! Those wheels really do the job! Is it lowered? or is it the 18' rims?
Bye For Now <img src="graemlins/xyxwave.gif" border="0" alt="[bigbye]" /> </strong><hr></blockquote>
If the power output feels low, there are only three things that can be wrong:
1. Boost is too low (wastegate problem)
2. Not enough air is getting into the engine (induction leak)
3. Fuel is not reaching the engine (fuel filter, fuel pump, etc.)
#3 will add other driveability problems so I think we can rule that one out. #1 should be easy to test with a simple boost gauge tapped into your CBV vacuum hose.
#2 is most likely. More than likely, your CBV is torn and leaking boost back into the non-pressurized side of the intake. Even though these test ok, they are known to fail, it's not a matter of if, but when. You should at the very least replace it with a 993 valve or better yet, replace it with a Forge or Baileys valve. I use a Forge valve and notice a big difference in performance from the 993 valve, especially on the fast shifts, it holds boost much better. With the higher boost I run, it makes an even bigger difference.
So, first, replace the CBV even if the shop says it's good. Second, check your boost pressure and report back.
Thanks for the compliments. The wheels are 18" from a 993 and the car is lowered using a RUF suspension. The combo works quite well on the street and track.
I finally got the 2pc 3.8RS splitter in, will get that installed soon.
fc-racer