Engine Toast?
#1
Racer
Thread Starter
Engine Toast?
Lapping day at the track today. Car running good until sudden loss of power. Pulled into pits, car running on 3 cyl. Checked plug wires, injector wires, vacuum hoses etc, all OK. Limped home slowly and did compression check:
#1 - 145 #2 - 60 #3 - 0 #4 - 120
#1 - 155 #2 - 65 #3 - 0 #4 - 130 With oil added
Yes those are "ZEROS"!!!
No coolant in oil or oil in coolant. No smoke from exhaust. #1,2,4 plugs tanish greyish, #3 oily black.
I have spark and fuel at all cylinders.
At fist I though head gasket with #2 and #3 low, but a ZERO? Could a valve be burned or stuck open? there is no unusual valve train noise.
Looks like the head is coming off at the very least. Anyone seen this before?
#1 - 145 #2 - 60 #3 - 0 #4 - 120
#1 - 155 #2 - 65 #3 - 0 #4 - 130 With oil added
Yes those are "ZEROS"!!!
No coolant in oil or oil in coolant. No smoke from exhaust. #1,2,4 plugs tanish greyish, #3 oily black.
I have spark and fuel at all cylinders.
At fist I though head gasket with #2 and #3 low, but a ZERO? Could a valve be burned or stuck open? there is no unusual valve train noise.
Looks like the head is coming off at the very least. Anyone seen this before?
#2
Nordschleife Master
Sounds like buggered head at the very least, maybe burnt valves on #2 and #3... my guess is fuel related issue... 2 and 3 shoot together I believe (1-4 and 2-3 if I recall correctly)... injector harness ate it and took out your valves with massive shots of fuel or spray after valves were closed?
I'm just making guesses at this point... Sorry for the dammage, but post pics and writeup of the cause and aftermath...
I'm just making guesses at this point... Sorry for the dammage, but post pics and writeup of the cause and aftermath...
#3
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All stock injection is batch fire. All injectors fire every time. 3 times against a closed valve, once against an open valve. If you follow the injector wires back to the DME they bridge on a trace on the board. Just to correct the above...
Don't know what it could be but I would pull the head and take a look.
Don't know what it could be but I would pull the head and take a look.
#4
Nordschleife Master
All stock injection is batch fire. All injectors fire every time. 3 times against a closed valve, once against an open valve. If you follow the injector wires back to the DME they bridge on a trace on the board. Just to correct the above...
Don't know what it could be but I would pull the head and take a look.
Don't know what it could be but I would pull the head and take a look.
#6
Nordschleife Master
Sounds like burnt exhaust valve(s). #2 is probably has a very tiny piece missing causing slight compression. You can do a leakdown test and listen for where the air is escaping from. Most likely it will be out of the tail pipe.
If its just a burnt valve, find replacements and then find out why it happened.. most of the time i have not seen collateral damage as a result. My friend (Jeeper31) recently burnt a valve on the #1 cylinder last year, replaced the valve and redid the headgasket this winter and the car is back out on the track again.
If its just a burnt valve, find replacements and then find out why it happened.. most of the time i have not seen collateral damage as a result. My friend (Jeeper31) recently burnt a valve on the #1 cylinder last year, replaced the valve and redid the headgasket this winter and the car is back out on the track again.
#7
Lazer Beam Shooter
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Lapping day at the track today. Car running good until sudden loss of power. Pulled into pits, car running on 3 cyl. Checked plug wires, injector wires, vacuum hoses etc, all OK. Limped home slowly and did compression check:
#1 - 145 #2 - 60 #3 - 0 #4 - 120
#1 - 155 #2 - 65 #3 - 0 #4 - 130 With oil added
Yes those are "ZEROS"!!!
No coolant in oil or oil in coolant. No smoke from exhaust. #1,2,4 plugs tanish greyish, #3 oily black.
I have spark and fuel at all cylinders.
At fist I though head gasket with #2 and #3 low, but a ZERO? Could a valve be burned or stuck open? there is no unusual valve train noise.
Looks like the head is coming off at the very least. Anyone seen this before?
#1 - 145 #2 - 60 #3 - 0 #4 - 120
#1 - 155 #2 - 65 #3 - 0 #4 - 130 With oil added
Yes those are "ZEROS"!!!
No coolant in oil or oil in coolant. No smoke from exhaust. #1,2,4 plugs tanish greyish, #3 oily black.
I have spark and fuel at all cylinders.
At fist I though head gasket with #2 and #3 low, but a ZERO? Could a valve be burned or stuck open? there is no unusual valve train noise.
Looks like the head is coming off at the very least. Anyone seen this before?
I had this same thing happen to me on the same cylinder too, number 3. Zero compression in that cylinder. The car sounded like a clankey diesel truck. The vaccuum line popped out of the intake manifold, screwing up the fuel pressure which resulted in, yep John called it, a burnt valve.
Here is a pic of my zero PSI valve.
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#8
Racer
Thread Starter
Thanks for the replies and support guys.
That's terrible. How many miles do you have on your car?
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215,000 Kms (133,000 miles)
Thats a good chunk out of that valve rock. Where did all the metal go?
When I got the car in the fall, #3 was already slightly low. During the winter I had replaced all the vacuum lines and found some that were quite ratty. Looks like I just finished off the weak link.
That's terrible. How many miles do you have on your car?
__________________
215,000 Kms (133,000 miles)
Thats a good chunk out of that valve rock. Where did all the metal go?
When I got the car in the fall, #3 was already slightly low. During the winter I had replaced all the vacuum lines and found some that were quite ratty. Looks like I just finished off the weak link.
#9
Rennlist Member
John's right - the 4 injectors fire in pairs - 1 & 4 and 2 & 3. One firing is against the back side of the intake valve when it's closed, the other when it's open.
It could also be a mechanical problem - like a broken valve spring and a retainer that failed...
Either way, time to pull the head!
It could also be a mechanical problem - like a broken valve spring and a retainer that failed...
Either way, time to pull the head!
#10
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Sounds like a burnt valve - typically that will be accompanied by a ‘chuffing’ noise at idle and some occasionally back firing.
Its one of the least expensive fixes when it comes to a zero compression reading!
Burnt valves are usually caused by high EGTs….which are common with the combination of lower AFR and retarded ignition timing.
Its one of the least expensive fixes when it comes to a zero compression reading!
Burnt valves are usually caused by high EGTs….which are common with the combination of lower AFR and retarded ignition timing.
#13
Racer
Thread Starter
At the time, the engine had ~3000 miles on it when this happened.
Yesterday 10:01 PM
Yesterday 10:01 PM
Just curious, where are you going to send your block too? Are you going to use someone in canada?
How much will that cost?
How much will that cost?
#14
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"John's right - the 4 injectors fire in pairs - 1 & 4 and 2 & 3."
Actually, 1 and 2 are wired together, as is 3 & 4.
Actually, 1 and 2 are wired together, as is 3 & 4.
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#15
Racer
Thread Starter
If I understand correctly, the injectors fire on the intake valve side. How does this contribute to the exhaust valve being burned? Just by an over rich mixture? If so, you would think #2 plug would look black as well. #2 looked the same as #1 & #4.