compression testing
 

Hi all,

I appreciate this may not be the right section to post but I need a general advice please.


I have a nissan skyline r34 bought few days ago and feels really weak . I think the gasket between the main output from turbo and the pipe is gone and it is leaking .



To give u an idea my 0 60 is around 9 seconds compared to 5 or 5.8 ish that this car is expected to do.


Would the leak cause such a big power loss if it is not in the fresh air side but where the exhaust fume are exiting the turbo ?

I am going to create a soup and water and test it as a bit curious but in the meantime did a compression test

heart attack is further below.

Here is how I conducted my test ,

1. engine ran for 10 minutes to warm up while intake manifold and dump valve and number of other things were disconnected so the car was running rough but couldn't be asked to put all the pipes back .

2.all plugs out .

3.accelerator floored to ground and 5 turns on each cylinder.

4.assumed cylinder 1 is the one closet to radiator ( is that right)?
results were :

Dry :
C1 189
C2 175
C3 129
C4 199
C5 60
C6 165

C5 is where I was about to burn the car !

again did wet by pouring a bit of my r6 oil into the lid of the 4 litre gallon it came with and do another test and result was:

C1 225
C2 200
C3 151
C4 205
C5 85
C6 195

So that suggested C5 and C3 are gone but I didn't give up.


I tried again for C3 and C5 . I don't know whether they would be called dry or wet test as a bit of oil was there but what I saw shocked me :

2nd test
C3 180
C5 200

3rd test
C3 191


I was tired so did the 3rd test only for c3.

how is this possible ? my view is the engine was a bit dusty and also when removed the fused box there was tons of dust as if the car has been into some sort of rally racing .

the cover which covers the plugs and is plastic cracked off in some areas and shed into pieces as it may not have been opened for a long time hence I was seeing spider web and all sorts.


when opened the spark plugs the threads were filthy I think so the area close to them and because I didn't have an air blower I just blew it my self .

I am thinking the cause for the potential false alarm on c5 and c3 is :

1.the thread was not clean and maybe the gauge had not gone in all the way . when testing c5 the sound was different as almost no pressure is getting built up.

or

2.engine had cooled down but this is irrelevant in my view as the engine bay was still hot but colder than when I initially did the test .

or

3. because it was a one man test , the gauge was left in the bay and I was doing the starting so could have been it was positioned incorrectly hence ... but unlikely .


I should say I heard a bang sort of sound few times, is that ok?
i removed two of the engine fused which did shut the engine but could be they were not the fuel fuse. if fuel goes in, does it cause any issue ?

I will do another test tomorrow as soon as back home and will report back but please do help me as if it is faulty, I will return the car .

my gauge is laser tool from machine mart for £20 .

finally some bits from the plastic stuff from the lid were shredded to pieces and went inside the spark plug hole. i wasn't concerned much as they would just burn or thrown out of the exhaust port considering it was a brittle plastic . is that ok ?