'91 S4 TB tensioner/WP question
#1
Instructor
Thread Starter
'91 S4 TB tensioner/WP question
Hi All,
I am working through my car - essentially following up on the things that have been done and should have been done. Anyway, initially I wasn't going to dig into the cambelt area as I have bills fron the PO that it has been done - but well you know while you are already there you might as well etc.....
Glad I did it now, as this is what I found
tensioner puller bolt migrating out
no clamp on tensioner boot
and nice gasket on waterpump now I know where the glup on the water bridge came from.
Nothing fatal but not ideal. On the test runs the car ran fine - no TB warning light, no overheating in summer town traffic. Water pump has case marking from 95 so it has been replaced at least once, the belt was replaced in 2007, that was 10,000 miles ago. No idea when water pump was replaced.
So what now? Check/refill tensioner and new belt/take off water pump put new gasket on/Porkentensioner and new waterpump?
Well, while I ponder that gives me time to do the intake R&R. Isn't WYAIT great - this all started as replace a fuel tank gasket and check ATF. I mean that in good way.
Oliver
I am working through my car - essentially following up on the things that have been done and should have been done. Anyway, initially I wasn't going to dig into the cambelt area as I have bills fron the PO that it has been done - but well you know while you are already there you might as well etc.....
Glad I did it now, as this is what I found
tensioner puller bolt migrating out
no clamp on tensioner boot
and nice gasket on waterpump now I know where the glup on the water bridge came from.
Nothing fatal but not ideal. On the test runs the car ran fine - no TB warning light, no overheating in summer town traffic. Water pump has case marking from 95 so it has been replaced at least once, the belt was replaced in 2007, that was 10,000 miles ago. No idea when water pump was replaced.
So what now? Check/refill tensioner and new belt/take off water pump put new gasket on/Porkentensioner and new waterpump?
Well, while I ponder that gives me time to do the intake R&R. Isn't WYAIT great - this all started as replace a fuel tank gasket and check ATF. I mean that in good way.
Oliver
#3
Instructor
Thread Starter
some more questions.
here are photos of the cam and oil pump gears.
Looking at the engine from the front:
Photo 1 is left cam, photo 2 right cam, photo 3 oil pump. The right one has more wear and more at the back of the gear.
They are worn but is there a couple thousand miles life left in them?
Also re the previous post. Some install the WP gasket dry some use a bit of blue RTV sealant on the gasket, but mine seems to fall in neither camp. So should I remove pump and change gasket or just leave as it is not leaking?
here are photos of the cam and oil pump gears.
Looking at the engine from the front:
Photo 1 is left cam, photo 2 right cam, photo 3 oil pump. The right one has more wear and more at the back of the gear.
They are worn but is there a couple thousand miles life left in them?
Also re the previous post. Some install the WP gasket dry some use a bit of blue RTV sealant on the gasket, but mine seems to fall in neither camp. So should I remove pump and change gasket or just leave as it is not leaking?
Last edited by oaros; 07-24-2011 at 07:36 AM. Reason: correction
#4
Rennlist Member
Any makers marks on the WP? If it is a "no name " pump then my personal feeling would be to go through the entire TB/WP system with a fresh setup. If the pump is a quality pump (Porsche or Laso) then a tensioner rebuild (or Pksn'r install) with new belt and cam/OP gears would be sufficient. Just my opinion. Once the coating on the cam gears wears through to the aluminum the wear rate increases dramatically. Failure of the TB system on 32v cars usually leads to $$$ in repairs. The WSM calls for the WP gasket to be installed dry. However, I used a little RTV on my install as there were a couple of minor imperfections in the sealing surface of the WP I installed. Hope this helps.
Mike
Mike
#5
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Gears are all on there way out - sorry. Mike is right once the spray on coating goes they wear quickly.
The new cam gears are expensive but much harder and in theory should last longer. A new oil pump gear will be steel.
I always use some gasket goo on the water pump gasket - a very thin smear on both sides.
Something tells me that is a Porsche pump - however you do not know if it is a rebuild or not. Go with a Laso pump unless you have a $1000 for a new Porsche one.
The new cam gears are expensive but much harder and in theory should last longer. A new oil pump gear will be steel.
I always use some gasket goo on the water pump gasket - a very thin smear on both sides.
Something tells me that is a Porsche pump - however you do not know if it is a rebuild or not. Go with a Laso pump unless you have a $1000 for a new Porsche one.
__________________
Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission? George Layton March 2014
928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."
Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission? George Layton March 2014
928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."
#6
Instructor
Thread Starter
Thanks guys.
I worked my way through the oil mess (my valley looks like a primordial landscape) and got some numbers off the pump.
the pump has the casting number 928.106.140.0R so it's a Porsche one, but rebuild or not who knows.
Apart from the 95 data stamp there is this number: 7533/FZ
Anyone know what that means?
Well, I guess it's time to start ordering parts.
Thanks
Oliver
I worked my way through the oil mess (my valley looks like a primordial landscape) and got some numbers off the pump.
the pump has the casting number 928.106.140.0R so it's a Porsche one, but rebuild or not who knows.
Apart from the 95 data stamp there is this number: 7533/FZ
Anyone know what that means?
Well, I guess it's time to start ordering parts.
Thanks
Oliver
#7
Former Sponsor
So, the biggest problem that you have is the oil that is getting all over the water pump and the timing belt. Cure the oil leak first and then completely clean the entire belt area.
The pump in the picture is a factory Porsche pump....they are the only ones that have a date stamp, that is on the left hand side of your first picture. It was manufactured in 1995, which means it got installed, after this date. I'm going to guess that the belt was from Porsche, also.
You are in an interesting spot. What should you do?
I see vehicles exactly like this, on a regular basis and have to figure out what to do, all the time....and requires a bit of logic to proceed.
Certainly, you could replace the gears, the water pump, the belt, and everything that touches the belt. However, if the belt looks good...still soft and with no brittleness on the teeth....and the water pump is not leaking, I'd clean the whole area up, tension the belt, and forget it for 10,000 miles....just keeping an "ear" open for any signs of water pump bearing noise....which everyone should do...all the time.
The gears are just starting to wear and will run perfectly well for another 10,000 miles....think of it like this: You just looked at your brakes and the rotors are worn below the minimum wear specification and the pads are half worn....why not let the pads wear out and get that "free" extra mileage out of the parts?
Obviously, if there is any question about the condition of the belt, it will need to be replaced. Again, interesting decision time. If you have the money, replace everything. If you are trying to save some money, throw a Gates Belt on it (stock style), rebuild the tensioner, clean everything up and forget it. Sure it won't last for 40,000 miles, but you will get another 20,000 miles out of those gears before they are completely junk.
The pump in the picture is a factory Porsche pump....they are the only ones that have a date stamp, that is on the left hand side of your first picture. It was manufactured in 1995, which means it got installed, after this date. I'm going to guess that the belt was from Porsche, also.
You are in an interesting spot. What should you do?
I see vehicles exactly like this, on a regular basis and have to figure out what to do, all the time....and requires a bit of logic to proceed.
Certainly, you could replace the gears, the water pump, the belt, and everything that touches the belt. However, if the belt looks good...still soft and with no brittleness on the teeth....and the water pump is not leaking, I'd clean the whole area up, tension the belt, and forget it for 10,000 miles....just keeping an "ear" open for any signs of water pump bearing noise....which everyone should do...all the time.
The gears are just starting to wear and will run perfectly well for another 10,000 miles....think of it like this: You just looked at your brakes and the rotors are worn below the minimum wear specification and the pads are half worn....why not let the pads wear out and get that "free" extra mileage out of the parts?
Obviously, if there is any question about the condition of the belt, it will need to be replaced. Again, interesting decision time. If you have the money, replace everything. If you are trying to save some money, throw a Gates Belt on it (stock style), rebuild the tensioner, clean everything up and forget it. Sure it won't last for 40,000 miles, but you will get another 20,000 miles out of those gears before they are completely junk.
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#8
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Greg,
I could see it was a Porsche casting but plenty of rebuilt (aftermarket) Porsche pumps out there.
Need to see maintenance history to know its Porsche for sure.
I like the way you think though 8>).
Roger
I could see it was a Porsche casting but plenty of rebuilt (aftermarket) Porsche pumps out there.
Need to see maintenance history to know its Porsche for sure.
I like the way you think though 8>).
Roger
#9
Former Sponsor
Anyway, that is the method of how I tell them apart, at a glance.
Seriously, if I changed gears, water pumps, and belts on every car that I saw with gears that looked like this....and every customer could afford to change them, I'd have to open another shop just to handle that work.
#10
Captain Obvious
Super User
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My brother's S4 gears looked like these or maybe slighly more worn. Considering he only drives it maybe 2000km a year, decided to leave them. I've replaced/rebuild pretty much everything besides the gears: new pump, rebuilt the tensioner, new rollers, all front seals, and a new belt. I figured at his rate, the gears should last another decade and by then, it will need a new belt anyways, so I'll replace the gears then. His car has,I think, around 400K kms and the fron end was hidden under 1/4" of oil/dirt. Just liek Greg said, clean it up really well before doing anything.
#11
Under the Lift
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If the pictures are representative of the entire gear surface, the right side cam gear is much better than the left. That gear wears much more slowly than the left cam gear and definitely could be left alone until the next belt change interval. The left cam gear and oil pump gear have wear through of the coating all the way across at least some teeth. That where I consider replacing it, as I don't want to have to deal with it for another 60K miles (belt change interval) although, I agree with Greg's position that it is a judgment call and all these gears have some useful life left in them.
Make sure you check the plastic bushings in the tensioner arm - the arm should have no play if the bushings are not worn. If any play, knock the old bushings out and press new ones into the arm one at a time with a C-clamp or vice - they are brittle plastic and will chip with any less careful method. Chamfering the leading edge of the bushing with a file before insertion helps to get them started.
Make sure you check the plastic bushings in the tensioner arm - the arm should have no play if the bushings are not worn. If any play, knock the old bushings out and press new ones into the arm one at a time with a C-clamp or vice - they are brittle plastic and will chip with any less careful method. Chamfering the leading edge of the bushing with a file before insertion helps to get them started.
#12
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If it were mine, I would clean it up, put a clamp on the tensioner boot (if the boot is still soft and not split) and fill it, check the tensioner arm for ANY perceptible loosness, tighten the loose bolt, check and tension the belt, and drive it.
#13
Instructor
Thread Starter
Thanks to all.
I'll go with the advice, nice that it supports what I was hoping for.
When I bought the car I was clear to me that it had just slipped onto the wrong part of the maintenance curve but felt it was an acceptable risk. I reserved the some of the budget for parts. Getting back to working on cars after a 20 year break is great. Rennlist and the great help and support here was a major factor in this.
Anyway, plan looks like this. Check/Fix tensioner, new T belt, deal with the mess under the intake - put everything together. Drive it. Then find and fix the last 20% in round 2.
Oliver
I'll go with the advice, nice that it supports what I was hoping for.
When I bought the car I was clear to me that it had just slipped onto the wrong part of the maintenance curve but felt it was an acceptable risk. I reserved the some of the budget for parts. Getting back to working on cars after a 20 year break is great. Rennlist and the great help and support here was a major factor in this.
Anyway, plan looks like this. Check/Fix tensioner, new T belt, deal with the mess under the intake - put everything together. Drive it. Then find and fix the last 20% in round 2.
Oliver
#14
Former Sponsor
Thanks to all.
I'll go with the advice, nice that it supports what I was hoping for.
When I bought the car I was clear to me that it had just slipped onto the wrong part of the maintenance curve but felt it was an acceptable risk. I reserved the some of the budget for parts. Getting back to working on cars after a 20 year break is great. Rennlist and the great help and support here was a major factor in this.
Anyway, plan looks like this. Check/Fix tensioner, new T belt, deal with the mess under the intake - put everything together. Drive it. Then find and fix the last 20% in round 2.
Oliver
I'll go with the advice, nice that it supports what I was hoping for.
When I bought the car I was clear to me that it had just slipped onto the wrong part of the maintenance curve but felt it was an acceptable risk. I reserved the some of the budget for parts. Getting back to working on cars after a 20 year break is great. Rennlist and the great help and support here was a major factor in this.
Anyway, plan looks like this. Check/Fix tensioner, new T belt, deal with the mess under the intake - put everything together. Drive it. Then find and fix the last 20% in round 2.
Oliver
Now you are good to go.