Strange sound from rebuilt engine...
#31
Rennlist Member
Peter,
You can pull the retainer cap off the tensioners and take a peak. One way to find if the tensioner is an issue is to pull the coils and turn the car over a bit without it running. It will make a very mechanical sound. You can hear the chain slap at the chain covers without the engine running. You changed all the lifters and it's pretty hard to put them in wrong. Did you clearly mark the exhaust and intake lifters? They are different at the top for oiling the cam shaft. If you have them reversed this would cause oiling issues.
You can pull the retainer cap off the tensioners and take a peak. One way to find if the tensioner is an issue is to pull the coils and turn the car over a bit without it running. It will make a very mechanical sound. You can hear the chain slap at the chain covers without the engine running. You changed all the lifters and it's pretty hard to put them in wrong. Did you clearly mark the exhaust and intake lifters? They are different at the top for oiling the cam shaft. If you have them reversed this would cause oiling issues.
#32
Race Director
If OP saw 1bar when not warmed up, that would be significant cause for concern.
#33
Burning Brakes
Thread Starter
Peter,
You can pull the retainer cap off the tensioners and take a peak. One way to find if the tensioner is an issue is to pull the coils and turn the car over a bit without it running. It will make a very mechanical sound. You can hear the chain slap at the chain covers without the engine running. You changed all the lifters and it's pretty hard to put them in wrong. Did you clearly mark the exhaust and intake lifters? They are different at the top for oiling the cam shaft. If you have them reversed this would cause oiling issues.
You can pull the retainer cap off the tensioners and take a peak. One way to find if the tensioner is an issue is to pull the coils and turn the car over a bit without it running. It will make a very mechanical sound. You can hear the chain slap at the chain covers without the engine running. You changed all the lifters and it's pretty hard to put them in wrong. Did you clearly mark the exhaust and intake lifters? They are different at the top for oiling the cam shaft. If you have them reversed this would cause oiling issues.
I've been doing some searching/reading and came across someone on another forum who installed the tensioners upside down. They described the noise as a deisel truck sound which is exactly the sound I have. So I will go with that idea for now, remove the caps and take a look.
Just to confirm - I should be seeing the small hole at the end of the tensioner indicating correct orientation? If the hole is not there that would indicate I have found my problem?
Thank you all for the help! I will report back my findings.
#34
Burning Brakes
Thread Starter
So, today, on cold start-up I have 1.5 which slowly drifts down to 1 at idle. When I kick it up to 2K rpm I get a pressure increase in kind. More to come tomorrow...
Last edited by Vorsicht; 02-06-2013 at 11:04 PM. Reason: Anal Retentive Disorder
#35
Race Director
#37
Rennlist Member
You should see a small hole at the top of the tensioner. The retainer cap has an oil passage on each side that allows oil to flow in and pump up the tensioner. That oil passage then continues onward to the feed tube you see located that connects to the cam tower. If your restricting that flow then you see how vital it is to get it corrected.
#40
Burning Brakes
Thread Starter
Mid-day update:
Removed left tensioner cap. Oil hole pointing up. Confirmed it is the left tensioner (longer of the two). Cleaned and resealed. At least the left is correct.
Before moving on to the right I started up the car. Pressure at start-up: 4 Bar. As the engine warms up the pressure slowly drifts down to below 1. Pressure bounces up with RPMs. At the 15 minute mark the pressure light came on and I shut the car down. Noise has not abated.
Removed left tensioner cap. Oil hole pointing up. Confirmed it is the left tensioner (longer of the two). Cleaned and resealed. At least the left is correct.
Before moving on to the right I started up the car. Pressure at start-up: 4 Bar. As the engine warms up the pressure slowly drifts down to below 1. Pressure bounces up with RPMs. At the 15 minute mark the pressure light came on and I shut the car down. Noise has not abated.
#44
Burning Brakes
Thread Starter
Yes, I tried running the car to get the lifters to pressurize. Not working thus far. Also tried pulling dme relay and turning the engine over. No unusual noise while doing this. I do not have a compressor at the moment so I can't do compression/leakdown yet. Did I miss anything you suggested? BTW, the heads were done by Steve at RS.
#45
RL Technical Advisor
Hey Peter,
Did you split the case for this rebuild?
If so, there are some very serious issues about oil pump sealing rings that cause VERY low oil pressure.
Let me know!
Did you split the case for this rebuild?
If so, there are some very serious issues about oil pump sealing rings that cause VERY low oil pressure.
Let me know!