I posted here because I don't think this is newbie problem...

My frined just bought a 1997 Eagle Talon TSI. W/ a little over 100K on it. The timing belt looks old and worn. But no cracks or missing teath... I am sure it needs to be replaced regardless of the verdict here.

He bought it yesterday. It has not been driven for 6+ months and it idled a little low. It made no noise and pulled fairly hard on acceleration and there were no signs of leaks or smoking or anything. I found that there was no vacuum line on the stock FPR, and the port on the intake was wide open tooWTF . This would explain the idle issue, right?

So this morning he tried a hard lauch for the first time. He revved it to 4500 rpms and dumped the clutch... Not a nasty lauch but just a hard launch. After this, a knocking noise developed that distinctly sounded like my 1g when she jumped timing and bent all the intake valves (just not as many knocks over time as you rev it a little). We noted the oil level was very low (barely showed oil on the dipstick). We found that there is a leak somewhere near the oil filter housing. We are having a hard time tracking it. Has there been any common DSM problems with a oil leak in this area?

Either way, the noise was not comming from the oilpan but from the valve cover. I brought the crank to TDC and the timing marks on the cams line up. So I was like WTF ! We added oil and the knock persisted. The engine was fully warm, wo we pulled the plugs and removed the uicp and, as I held the gas pedal to the floor, we ran a basic compression check on each cylinder. 1-4 respectively: 141psi, 121psi, 141psi, 141psi. IIt is possible that compression tester was not tightened all the way, but I had it tightened equally for each cylinder. There was no coolant in the oil, neither was there any smoke/steam from the exhaust. So I am ruling out a headgasket...

Could 1 or more of the number 2 cylinder valves be bent? Why would they bend, if the timing belt has not jumped any teath? Could running it with low oil and/or low oil pressure have caused a lifter to stick and, consequently, leave the valve open after the cam lobe has passed? This could have allowed the valve to contact the piston top, right?

1. So, should I pull the head (I think that it is obvious that I should)?
2. Am I to expect a bent valve?
3. Can a lifter stick open when low on oil and/or oil pressure?
4. Where could that oil leak be coming from? (is it common for there to be an oil leak in that area? and where?)


Thanx for any insite you can offer,

hey matt, i have been searching ever since i got home and i found someone who said service limits on compression is 133. So 120 seems VERY low.

bane3d said:

I've seen posts like this before. I think one of the DSM Wisemen said that when you try to roll start an awd, you can cause it to skip timing. Who knows what the problem was before he tried to unload, but his bump starting it sounds like that is the culprit. I believe that fwd vehicles aren't susceptible to this, only awd.

d

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awww man. when the car cut off on me those couple times, i was rolling so i just let the clutch out and it started right back up and once it bucked real bad kinda like it does when you hit fuel cut. i wonder if that has anything to do with this.

another thing i found is that some people have had trouble with their auto tensioner, we need to check that.

First, the leak is probably coming from the water/oil cooler mounted on the filter housing. Pull the oil filter off and snug the mounting stud. Dont overtighten it because you can crush the cooling fins and then you would create other problems.

The knocking is more than likely the rear balance shaft. Low oil, very little run time, and high rpm's dont mix. Something usually gives and generally, the bs bearings are the first to go followed shortly by rod bearings. Sometimes the noise will sound as if it is coming from the vc but the bs noise tends to resonate throughout the engine and pinpointing it may be hard without a stethescope(sp?).

If timing marks still line up perfectly, chances of a bent valve are slim to none. With compression over 100 in all cylinders, chances of a bent valve are slim to none. Forget about the head at the moment and look elsewhere for the problem.

Another thing to look at would be the harmonic balancer(crank pulley). The outer ring will seperate from the hub and make contact with the frame rail also creating a knocking sound but usually can be pipointed easily. This is also a common problem with the 4g63, 1g and 2g.

From what I see, my money is on the rear bs bearings. The only way to verify this is to pull the oil pan and check.

thank you very much, i will do that tomorrow, i guess searching did actually pay off

i've been reading about how to check for a spun rod bearing, i definitly want to try that tomorrow. i've read that while the car is running pull the plugs one by one and if the noise stops then that's the one.

92awddsm said:

First, the leak is probably coming from the water/oil cooler mounted on the filter housing. Pull the oil filter off and snug the mounting stud. Dont overtighten it because you can crush the cooling fins and then you would create other problems.

The knocking is more than likely the rear balance shaft. Low oil, very little run time, and high rpm's dont mix. Something usually gives and generally, the bs bearings are the first to go followed shortly by rod bearings. Sometimes the noise will sound as if it is coming from the vc but the bs noise tends to resonate throughout the engine and pinpointing it may be hard without a stethescope(sp?).

If timing marks still line up perfectly, chances of a bent valve are slim to none. With compression over 100 in all cylinders, chances of a bent valve are slim to none. Forget about the head at the moment and look elsewhere for the problem.

Another thing to look at would be the harmonic balancer(crank pulley). The outer ring will seperate from the hub and make contact with the frame rail also creating a knocking sound but usually can be pipointed easily. This is also a common problem with the 4g63, 1g and 2g.

From what I see, my money is on the rear bs bearings. The only way to verify this is to pull the oil pan and check.

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Excellent and well explained advice! Therefore, it is very likely that we're hearing a BS bearing and since we have replenished the oil that this is the total extent of the damage.

My 1G, not 2G, Factory Service Manual does not delve into full shortblock teardown... How would we easily remedy this problem? I have never dismantled a BS assembly. Will this VFAQ eleminate the noise/problem, if the BS is the culprit?

Very good point about the compresion still being too high to bring an unseating valve into question. I am wondering now why the compression in the #2 cylinder is so low. The pressure difference is beyond the service limit, right?

the_jester said:

i've been reading about how to check for a spun rod bearing, i definitly want to try that tommorrow. i've read that while the car is running pull the plugs one by one and if the noise stops then thats the one.

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Absolutely! if this test doesn't eleminate the noise, then I guess it can be assumed that it is either a main bearing (the noise was muffled when I was listening in these areas) or it is BS bearing.

I'm still wondering about your compression on the #2 cylinder. . .

Thomas,

I'm putting some research I've done here so that we both can refer to them easily and so you can read it:

Rod Knock After T-Belt Install???
Loud knocking noise...Need help fast
Alright looks like a spun rod and maybe screwey crank???

Lets...
1. Double check the crank pulley.
2. Do the test for checking for a spun rod bearing.
3. Drop the oil and check for metal shavings.
4. Drop the oil plan and check the rod bearings for scores and such and check the balance shaft for play.

Hopefully all you'll have to lose out of this is a $50 bs eleminator kit or a crank pulley.

To anyone, should the rear BS have any wobble at all when pushing on it?

Knock completely stopped when we removed the plug wire from the #2 cylinder. This is also the same cylinder that showed a low compression number (all were 141 psi and this was 121 psi). WTF Would a knocking rod cause lower compression?

Thomas. we never dropped the oil!... I'll do that right now.

we couldnt drop the oil pan because all that stuff in the way. we can drain it but if there are shavings they might stay in the pan. oh well maybe some will come out. maybe enough to know.