car sitting for awhile, now no compression in 2 cylinders...

[Drewcool2]

My car has been sitting for 4 1/2 weeks now due to some clutch work. I finally started it up today and right away I heard about 10x the valvetrain noise, it ran extremely rough, and I had to struggle to keep it running. I thought it would get better with some time, but it never did. I have fresh 20-50 mobile 1, my oil pressure was fine, and my 272's were visibly getting plenty of oil up top. I did a compression check and cylinders 1 and 2 (driver side) had ZERO to 1PSI , while cylinders 3 and 4 had 165-170PSI. Adding oil to the dead cylinders only added like 2PSI.

What would likely cause this to happen? My motor ran great 4 1/2 weeks ago.

 

[90blacktsiawd]

Bump.

I'd really like any info on this too as I'm having about the same problem. Mine sat for about a month and a half due to tranny problems. Just picked it up last night from the garage i had the work done at. First they couldn't get it started from a dead battery, They charged it then it wouldn't turn over. They checked 2 cylinders for compression and both had 0! They kept canking it and finally it turned over. They check compression again and it was up to 130-140 across the board. I leave and get about a mile away when it sounds like something fell out of the engine bay, Like a wrench or a socket. I stop check and find nothing and everything looks to be ok. My oil pressure is a lot higher than normal. Almost up to the upper most bar on the stock gauge. I get back in pull out and maybe 100 feet up further i hear a tink, pop and the car just dies and it won't start again. They guys have no idea what could've happened. When you try to start the car there is a clicking noise that seems to be coming from thesprings when they decompress. We had the valve cover off when we noticed this. Any ideas guys?

Oh yeah one more thing. My valvetrain was louder than i ever heard it before. I thought it was just due to the fact that there was no oil in it at first and just had to wait for it to get through the system.

 

[Defiant]

Suspect jumped timing on startup.

 

[Drewcool2]

Suspect jumped timing on startup.

Could that be it? Cylinders 1 and 2 have zero compression, while 3 and 4 are fine. Wouldn't they all go down if the timing belt jumped?

 

[Rex2342]

Mine did the exact same thing as yours while I was driving it though. No comp in 1 and 2 but 3 and 4 were fine. Mine turned to be a blown HG.

 

[Drewcool2]

Mine did the exact same thing as yours while I was driving it though. No comp in 1 and 2 but 3 and 4 were fine. Mine turned to be a blown HG.

HG is kinda unlikely for me since it was just sitting for a month, but knowing these dsms...anything is possible I guess. I'm going to try to do a leakdown test tonight and pinpoint where its leaking. I'll post with results.

 

[gurrmanator]

rings are stuck because of bad oil or cloged ring lands...get some engine flush and get the motor hot(operating temp).rings are glued to the pistons because of gunk(build-up).

 

[rowlex]

first thing id do is check timing marks. AT LEAST check the cam timing marks...along with the timing mark on the harmonic balancer.

 

[Drewcool2]

Well did the leak down test. We put each cylinder TDC one at a time, and air was coming out the intake and exhaust really badly for both bad cylinders. The test gauge was at 100%. Also the timing belt skipped 3 teeth, which may explain some bent valves in those cylinders since I do have 272's in there. I don't know, is 3 teeth with 272's enough to bend valves?
Basically I need to pull the head to figure out exactly whats going on. I don't know what to do though because I really need this car, don't have much money, and I don't have time to fix it myself. Thinking about having my mechanic do it in his spare time, or some dsm shop. And what should I do while i'm in there besides new hg, head studs, and intake manifold gasket? Should I do the timing belt, tensioner, and water pump? I don't plan on keeping this car much longer, and the belt was just replaced 4k miles ago.

I will appreciate any input anyone has on what you think happened, and what I should do.

 

[rowlex]

do this: Pull the timing cover, re-align all the timing marks (if your pro you dont need to even pull the timing cover(just screw in the "special timing belt tool" remove tension from the belt, slip it off the cam gears and reset the cams to TDC put belt back on) then run another compression test.

 

[Drewcool2]

do this: Pull the timing cover, re-align all the timing marks (if your pro you dont need to even pull the timing cover(just screw in the "special timing belt tool" remove tension from the belt, slip it off the cam gears and reset the cams to TDC put belt back on) then run another compression test.

I would do that except even with one cylinder tdc, and the lobes on the cams pointing up(meaning valves should be sealed), air pours out intake and exhaust. And why would cylinders 1 and 2 have ZERO compression, and cylinders 3 and 4 be perfectly fine. Do you think it could really be timing? I'm not sure if timing could make that big of a difference on 2 cylinders and not on the other 2.

 

[DSMstatus]

i would suspect head gasket and the rings stuck in the grooves like mentioned above. but that would be unlikley that two pistons would have stuck rings. check timing mmarks and check head gasket.

 

[rowlex]

I would do that except even with one cylinder tdc, and the lobes on the cams pointing up(meaning valves should be sealed), air pours out intake and exhaust. And why would cylinders 1 and 2 have ZERO compression, and cylinders 3 and 4 be perfectly fine. Do you think it could really be timing? I'm not sure if timing could make that big of a difference on 2 cylinders and not on the other 2.

well, what do you have to lose?

If i remember correctly, pistons 1 & 4 (and their respective valves) fire/open at the same times, with pistons #1 and $4 up pistons 2/3 will be at the bottom of their stroke, thats why they may not hit. I've worked on a 2G that was off roughly 2 teeth it ran like shit, we re-timed it pro style like mentioned above it took 40 mins maybe and the thing ran a lot better afterwards. it's something to try that wont take you very long.


EDIT: sorry, I thought you said pistons 1 & 4 had no compression, not 1&2. I re-read and found that to be incorrect. It's still probably worth a shot to re-time everything and try again. Its not like you could do any further damage.

EDIT #2: this is mainly educated guess-style info; but when doing a leakdown test you can probably find out if it is the HG as well, by maybe removing the dipstick and water cap, listen for air/look for bublles..? I dont get how you could bend valves 1&2 since #2 should be at the bottom, when #1 is up top.

Can someone PLEASE confirm this??? (all i did was look it up on howstuffworks.com i just cant remember if the block I have at home is sitting with #1&4 up, almost certain it is tho)

 

[Rex2342]

Another thing I noticed with mine was this. While I was doing the compression check I could hear a hissing in 1 and 2. Mine blew about 1/4" of the gasket out right between 1 and 2 and it never smoked or anything. My boost gauge was reading zero vacuum until I reved it up a little, it was idling at like 400 rpms and would keep stalling if I didn't give it gas. Just check out every possible solution before you pull the head back off.

 

[Drewcool2]

How much do you guys think it would cost to have a shop replace a bunch of valves as well as all the valve guide seals. I would think that's all I would need done if I just bent some valves, correct? Lifters and rocker arms are likely ok to stay in there?

 

[gurrmanator]

its hard to say how much $$ until you pull the head off(200.00 ball park)

 

[Drewcool2]

I was looking to take my car to JNZ Tuning, since I hear they are in the philadelphia area and have a good reputation with dsm's. Does anyone know where they are located?

Anyone suggest a different shop to take off my head, replace my hg/timing belt stuff and repair any damage on the head? DSMotorsport is too far from me and TurboTrix just seems so busy all the time. Other than these 3 places I don't know of any other good dsm shops nearby. Satan costs too much, and I just don't like giving my car to any old shop...