Compression Test results on a 1.1 TU1M+ engine

[CactusJack]

Hi All

Just finished the compression test on the car as I finally bought myself a compression tester gauge.

The engine is a 1124 ccm TU1M+ engine and has some 16/17 years behind it.

Here are the results :

Dry:
Cyl number 1 -> 125 psi
Cyl number 2- > 115 psi
Cyl number 3 -> 115 psi
Cyl number 4 -> 120 psi

Wet:
Cyl number 1 -> 125 psi
Cyl number 2- > 120 psi
Cyl number 3 -> 120 psi
Cyl number 4 -> 130 psi

For the wet test i might have put a bit more oil in the 4th cylinder, hence the bigger PSI.

The only thing I know is that I've read / heard that there should be no larger differences between two cylinders (Haynes says 20%). I see here no bigger differences between cylinders but I've expected (and read here) that perhaps the values should be bit bigger. Could that be normal engine wear from time and usage or is there something nasty going on ?

As always thanks Everybody for comments / hints

[CactusJack]

forgot to mention it, i've done the measurement on a cold engine, guess I should repeat it on a warmed up engine, maybe the results would be a bit higher....

[welshpug]

did you hold the throttle open?

no point doing a warm test tbh, the numbers are even, your problem is elsewhere if there is ome.

[CactusJack]

True. Numbers should be the same cold / warm.

Hmmm at first I forgot about the throttle, then repeated it with the throttle to the floor. The numbers seemed to be the same. I'll repeat the test on weekend, maybe I missed something else.

Btw. the reason for doing the compression test was, because the head gasket was done recently, and after that I got quite of white smoke out of the exhaust. But that happened only after the car warmed up, and if I revved the hell out of it the smoke would stop. The car also was sitting for about a year so I guessed it might have been the condensation or old coolant from previously failed HG.

I wanted to check if the HG replacement might have had gone wrong or the cylinder head was cracked. Btw. on the HG job the cylinder head has been machined so warped head should not be the problem. It has not been magnafluxed though...

And even if it was a hg I assumed then low compression would be on 2 adjacent cylinders, not all four

Anyway thanks for the answer.

Cheers

[axsaxoman]

engien shoudl be running even with thsoe numbers--so if its rough as welshpug look somewhere else

[CactusJack]

Thanks for the answer.

Forgot to mention some facts, the engine does start and works. Doesn't seem to be running to rough though. If the timing was one tooth out or the valve weren't adjusted properly (had slack on the rockers ) that could /should also have an impact on the compression ?

[welshpug]

valve clearances can affect compression yes, easy enough to check and adjust.

one common thing that fails when a HG goes is the Lambda sensor, they don't like being steam cleaned with super heated coolant!

[CactusJack]

Thanks mate!

About that lambda, wouldn't that result in a Check engine light ? One of the rare things that I've never seen on my car is the check engine light during operation

[crpt2008]

Hi all it's an old thread but might be useful to others adding my own two cents.
On my 1124cc TU1M+ I've done similar job. Although in my case I replaced all valves, head gasket (standard), and the rest of the normal stuff, read water pump, timing belt... cleaned (not polished) intake and exhaust ports/manifold.
Notice I used a "standard" gasket on a machined head, as a result the compression should/must be slightly higher. So for the interesting stuff:

#1 160psi
#2 155psi
#3 157psi
#4 160psi