Lost compression first trip out!! help!

[shadywang]

Ok, so i finally finished my dsm. took it out for its first run, didnt enter any positive vaccuum, and i get home and hear a clicking sound. thought it was comming from the turbo, so i shut it down. waited a bit and started it back up. realized it was only running on 3 clyinders. did i compression test to find it was ok on 1,3,4, but like 2 - 3 psi on cyl. # 2. have a rebuilt new head with like 200 miles and a stock bottom end. heres the rest of my setup. any ideas what could have happened?? im gonna pull the head today i think to check things out.

1993 Talon TSI AWD
6 Bolt, stock internals
Walbro 255 pump
550 Cc injectors
5 Bar AEM map
Gm AIT Sensor
16G turbo, 2G manifold
Bushur Front mount
2.5 Exhaust
Everything else is pretty much stock parts.

Thanks again for looking

Ron

 

[TSIfreek]

Could have bent an intake valve. Check your timing marks again the belt may have slipped.

 

[shadywang]

heres a update:

took head off, all looks good. no bent valves or anything

Pistons and walls all look good, with no problems showing. had a bit of carbon around the 2nd cylinder, the one i lost compression in. im thinking maybe the guy who had the car before me didnt properly install the head gasket?? im gonna order a new head gasket and put it all back to gether to OE specs and see what happens. i guuess if it is a bad ring, ill know then. thanks!

Ron

 

[GTM]

heres a update:

took head off, all looks good. no bent valves or anything

Pistons and walls all look good, with no problems showing. had a bit of carbon around the 2nd cylinder, the one i lost compression in. im thinking maybe the guy who had the car before me didnt properly install the head gasket?? im gonna order a new head gasket and put it all back to gether to OE specs and see what happens. i guuess if it is a bad ring, ill know then. thanks!

Ron

I wish you had done more checking and discussions before pulling this down. You never posted what the other cylinders were or if you did it with wide open throttle or how many times you repeated the test.

At the minimum you must fill the inverted head combustion chambers with solvent and see if any valves leak then you must lap all the valves to make sure they are seating. To have 0 compression you would have noticeable piston/cylinder damage, a blown head gasket would also show burns beyond the sealing ring and would have probably pumping a lot of water and overheating. Head gaskets rarely suffer sudden catastrophic failure as you describe so I would want to know a lot more before just assuming this was a gasket failure. Did you ever recheck the head bolt torque before pulling it down.

Did it ever run right when you bought it?

Cheers,
GTM

 

[shadywang]

Ok. heres a bit more details for you. took the car out, didnt get on it for about 5 miles, turned around, started to ease into throttle, made like 10lbs. boost, ran really good. using AEM EMS setup with a map, and tuned to their specs with 550CC injecotors. i came back home, car was running on 3 cylinders once i started to let it cool down. i let it cool down, started it back up, did same thing. again, cooled it down, then did compression test, it was between 2 and 3 PSI on # 2 cylinder, around 150-160 on the rest. i did take the head off, and the cylinder walls look really good. no sign of wear or anything on pistons or cylinder walls. i should have checked the torque on the head bolts, but when i took them out, they felt like someone put them in with a impact. anyways, the story with the engine was it came out of a parts car i got, and it had a freshly rebuilt head (less then 200 miles ) then block is stock, with like 100K on it, but in really nice shape . i put it in my car, but never ran it. i did check the compression both before i took it out of the parts car and once it was in my car, with compression at about 165-170 each time.

anyways, i took the head to a machine shop today, and they are going to pressure test the head, and check it to make sure its flat. if that all comes back good, i ordered a new head gasket and im going to put it in and hope for the best. any more ideas?? thanks

Ron

I wish you had done more checking and discussions before pulling this down. You never posted what the other cylinders were or if you did it with wide open throttle or how many times you repeated the test.

At the minimum you must fill the inverted head combustion chambers with solvent and see if any valves leak then you must lap all the valves to make sure they are seating. To have 0 compression you would have noticeable piston/cylinder damage, a blown head gasket would also show burns beyond the sealing ring and would have probably pumping a lot of water and overheating. Head gaskets rarely suffer sudden catastrophic failure as you describe so I would want to know a lot more before just assuming this was a gasket failure. Did you ever recheck the head bolt torque before pulling it down.

Did it ever run right when you bought it?

Cheers,
GTM

 

[GTM]

...
compression test, it was between 2 and 3 PSI on # 2 cylinder, around 150-160 on the rest. i did take the head off, and the cylinder walls look really good. no sign of wear or anything on pistons or cylinder walls. i should have checked the torque on the head bolts, but when i took them out, they felt like someone put them in with a impact.
...
anyways, i took the head to a machine shop today, and they are going to pressure test the head, and check it to make sure its flat. if that all comes back good, i ordered a new head gasket and im going to put it in and hope for the best. any more ideas??

Though not firm, I've come across 2 different fresh built engines that have had 1 or more hydraulic lifters which have appeared to stick at max adjustment. This holds the valves open and resulted in very low or no compression, in one case it seemingly bent valves. If your head comes back with no valve problems then I would be suspect that something is going on with the hydraulic adjusters and must be cleaned, serviced, or replaced.

All I can impress upon you is to check and recheck your work. When doing a compression check you just go down the line and record your findings, then repeat any holes that are suspect. By that time you will have a seat of pants feeling for the cranking pattern and a low (or high) cylr will stick out.

The fact the head bolts came off with some resistance it probably didn't have a blown head gasket caused because they were not torqued.

Cheers,
GTM

 

[shadywang]

GTM,
im looking into getting new hydrolic lifters. JAM sells them for 160 for the set of 16, is that a good price ?? any other places you know of ?? thanks again for all your help!!

Ron

Though not firm, I've come across 2 different fresh built engines that have had 1 or more hydraulic lifters which have appeared to stick at max adjustment. This holds the valves open and resulted in very low or no compression, in one case it seemingly bent valves. If your head comes back with no valve problems then I would be suspect that something is going on with the hydraulic adjusters and must be cleaned, serviced, or replaced.

All I can impress upon you is to check and recheck your work. When doing a compression check you just go down the line and record your findings, then repeat any holes that are suspect. By that time you will have a seat of pants feeling for the cranking pattern and a low (or high) cylr will stick out.

The fact the head bolts came off with some resistance it probably didn't have a blown head gasket caused because they were not torqued.

Cheers,
GTM

 

[GTM]

GTM,
im looking into getting new hydrolic lifters. JAM sells them for 160 for the set of 16, is that a good price ?? any other places you know of ?? thanks again for all your help!!

I have no idea about prices, you will just have to search the Internet for sources. It seems that a lot of owners switch to mechanical lifters so you might find a good used set on eBay. Still you will need to inspect anything you put back in there also to clean the oil passages well so you don't introduce any contamination.

Cheers,
GTM