Stock R34 Gtt No Compression

[Crimpage]

Hi All,

I have a pretty crappy drama going on with my 34. I went away camping for a week from the 7th - 13th. Came back, took it up the road to get dinner it was all good. Drove it to work on the 14th and it was all good. Went to start it up on the 15th, and it no go :|

The car tries to kick over, you can hear the starter motor doing it's thing, but just doesn't get anywhere. You can hear that it's not even detonating the fuel, it just sounds like the starter turning over.

I had Lube Mobile out (because my car was at home and I didn't want to tow it somewhere). The guy checked the fuel pressure and said it was all good. He pulled the cover and fuel rails out and all of the spark plugs and started to test the compression in the cylinders.

#1: 50PSI

#2: 50PSI

#4: 40PSI

He didn't bother checking the rest. He told me that basically the engine is shagged and it will need to be replaced (not worth rebuilding). I'm having a hard time trying to think of what could go wrong trying to start a stock engine that compression would be lost in all of the cylinders? I understand the basic workings of an engine but do not know enough about them to be able to troubleshoot it / pull it down myself. I was just about to get it serviced, roadworthied and sell it...

So, my questions are:

1. Would could it be that could go wrong with it, that most compression in all cyliners would be gone.

2. Depending on ideas from question 1, what would be my best options? Should I take it to another mechanic and have them check it out? Is it AFU (All F***** Up) and I need an engine? Should I try and sell it broken as the rest of the car is in pretty awesome condition. Would fixing the engine be an economical option.

I'm hoping for some pretty open discussion. Thanks heaps for you help!

Cheers,

Dave.

[krzysiu]

#1 take it to a real mechanic. Lube mobile are a bunch of useless f**ks and chances are he probably didnt do it right.

The second wrong thing he sugested was to replace the engine. Its better to rebuild because you know everything is fresh. When you buy a second hand engine then you dont know what your getting.

For a car to lose compression in ALL cylinder would be some freak event, hence why i believe he did it wrong.

[Crimpage]

Hi krzysiu,

That's what I thought. Especially when starting a completely stock engine...

Anyone else have any idea's?

Thanks guys.

[paulr33]

timing belt may have snapped / come loose / shagged

= smashed everything

if the belt lets go, bolt snaps etc the pistons crown and it smashes all the valves

have seen it before - doesnt matter if car is stock or not

how many kms on the engine

[Crimpage]

84k

Would you hear that tho while you try to turn it over? Wouldn't it sould like sh*t?

Cheers

[Crimpage]

Anyone else have any ideas?

Thanks heaps!

[VB-]

get it re-tested. only call-out mechanic i've seen that has diagnosed a car right was a blown head gasket on an EA falcon, even then its about 50/50 he'd be right even if he guessed.

to suddenly lose all compression, its gotta be in the head, snapped belt or something, maybe tensioner has let go, moving the came timing heaps but not enough to smash it/make heaps of noise? dont know if thats possible but cant think of much else, if it genuinely has no compression that it.... again, get it retested by someone in the know

[Crimpage]

Hey everyone,

Sorry to bring up an old thread, but for an update and more idea's on this.

I had my brother come and have a look at my car with me on Saturday. Lube Mobile left the intake to the throttle body off and all of the coil packs off, so we went and bought a compression tester, and tested each of the cylinders. It came out to:

Cylinder # PSI

1 50

2 60

3 55

4 100

5 80

6 60

First thought. Yep, it's fked. My brother said for compression to be lost like that, something pretty major must have gone on. We checked the oil, no real telltale signs of damage there, no water froma blown head. So we decided to put it all back together and see if we could figure out which of the three major players it could be (Air, Fuel, Spark).

In the almost 3 months my car has been sitting in the front yard, my battery went flat so we bought a new one. We took the air filter out (K&N which looked pretty dirty). Connected up all the hoses that Lube Mobile took off...

She kicked over first go!!! Running as smooth as ever. WTF?!?! We decided we'd service it (Oil, oil filter, new air filter for now until i clean and oil the K&N, front and rear brake pads as they were low)

Did all that, took her for a drive from my house in Runcorn down to Jimboomba (25-30 minutes) to my brothers house, and back. All good. She has just as much power as she ever had and I'm sure it's as much power as it is supposed to have.

Basically my question is. What is the deal with the compression? SURELY my car would run like crap if the engine compression was really THAT bad! And, does anyone know what PSI an RB25Neo should be?

Cheers,

Dave

[666DAN]

Is your car the sedan with R33 wheels parked out the front? If so I wondered who owned that, I pass it almost everyday.

I would have thought the compression should have been up around the 150-170 mark and a lot more consistant than that :S

Funny how things go though, my ECU shat itself today, big puff of smoke as the ignition transistor split in half

[Crimpage]

Nah not me. I have the stock 34 rims and live in a culdersac.

I just had a read about checking engine compression and it suggested that I should do it with a warm engine as that helps the metal and gaskets expand giving a more accurate reading, and to do it will all of the spark plugs out to allow the starter to spin more freely. Think that would have any impact? I wouldn't think it would give that much of a wack reading from cold...

[1400r]

you and the mechanic did the comp test wrong would be the simple

and most obvious answer

[VB-]

did u hold the throttle open while testing?

[Crimpage]

no, just kicked it over...

[Turbotonic]

7PSI to 10PSI