They did use a compression tester, It has been proven working on other cars. On my car it showed 85-90 psi on all four cylinders.

They removed one plug at a time and did the test on each of the four cylinders in turn each time replacing the plug also so there is always 3 plugs and the tester in place on the engine.

I do have a nasty oil problem on the car which no one seems to be able to solve. Here

[Edited by alanjack - 10/4/2003 1:28:52 PM]

 

Very surprised that the other three plugs were left in during the test. Usually have the throttle wide open as well.

Les

[Edited by Leslie - 10/4/2003 5:39:40 PM]

 

Had my engine compression tested today and the out come was:

6.0.1 I have been told I should have expected approx 8.0.1.

Anyone want to shed anymore light on this?

Theories at the moment range from gaskets to the engine previously being in bits and having low compression pistons fitted. I have done approx 2,500 miles in the car since this engine was fitted(which I know nothing about) and found it to be very laggy and to be honest gutless below 4,500 rpm but after that it is very good.

The car was dynoed at 354bhp and cannot outrun Civic type R's, and even a friend's WRX with a cat back and K+N.

My spec is as follows:

UK Turbo running an STi4 Engine
TD05 front entry
HKS FMIC
GReddy Iridium plugs
Apexi AVC-R electronic boost controller set at 1.4bar/20.3psi
Apexi Power FC
Fuel pressure regulator
HKS SPF air filter
Up-rated fuel pump (250litres p/h)
Thamesvalley Motorsport up-rated oil pump
Injectors 440cc
Jap Innovations downpipe
HKS Hiper Muffler exhaust system
X-Eddy Racing clutch

Many thanks in advance

 

Alan,

How was the compression tested/measured ?

Mark.

 

I'll find out.

BTW Mark, your synchro set is superb

 

Alan,

The reason I ask, is that I can't see ANY WAY you could be running as low as 6:1, regardless of what gaskets were used.

I think you'd need to have gaskets 5mm + thick to get anywhere near.

If they used a compression tester, what PSI were the cylinders showing ?

Thanks

Mark.

 

Alan,

I'm pretty dure that isn't the right way to do the compression test.

AKAIK, the test should be done when the engine is warm. ALL of the plugs should be removed, and the crank sensor disconnected.

Personally, I would have them redone.

Ideally, have a cylinder leak down test done.

Mark.

 

The crank sensor was removed, forgot to say that

What is a cylinder leak down test?

Who could do one?

 

If the pressures are true then you have a serious problem but ... all plugs should be removed and the engine cranked over 10-12 times for each cylinder to take the cylinder pressure, test should be done with warm engine (ie from fully hot).

Std pressure should centre around 145 psi with no more than 7psi difference cylinder to cylinder.
Compression ratio can vary by plus/minus 0.2 as std though.

cheers

bob

 

How serious and could this be attributed to my oil leak?

 

You say you have low compression pistons fitted, I guess the answer could lie there but at that level its never going to drive off boost well. 6:1 is unheard of, 7.4 or so yes.

The amount of oil in your pipework indicates a serious amount of blow by though and that could be the problem with the compression as well, at a guess I'd say you need to get it investigated properly ie pistons out and checked etc.

bob

bob

 

Bob,

I do not know if there are low compression pistons in the car, I have only had the engine in the car for 2,500 miles and know nothing about it's history, I am though waiting for more information on that. I expect though, that the leak and low compression are possibly linked and would expect the supplier to fix the problem as he is a good man.