Compression Test

[hanyou]

hey guys my car has been in the garage since the start of october and its set to get new turbos due to the blown ones, however i want to check the compression b4 towing it off to the workshop and finding out that i need a rebuild. i havnt bought the turbos yet incase i need a rebuild, because if i do i will probaly sell the car as is

i dont know what other tools you need for compression tests but ive got socket set already so if anyone can come and do a test for me id more then appreciate it! i can offer a case of beer if anyones interested! since thats the usual form of currency around here for help lol

im in the western suburbs of sydney (blacktown area)

[blk180]

i have comp thingy but car sould be warm i think to test. I live just down the road if you need a hand let me know when, i do shift work so maybe be hard finding a day when we are both off.

working arvos all week and off next monday and tuesday

[Beer Baron]

yeah, engine needs to be at operating temp to get an accurate reading.

[hanyou]

wel i started the car for the first time since i knew it was blown (october) and it idles fine with no unordinary noises.. i let it idle till it was upto operating temps.. im assuming my engine is fine by the looks of how its going! but yeah just to make sure

blk180: cool would it be ok for a monday or tuesday next week? anytime monday but tuesday would have to be before about 2pm.

[blk180]

Yer no worrys could have done it today as well too but next monday or tuesday good

[hanyou]

cool will give you a PM closer to monday then! thanks

[wrxhoon]

In this case you don't need accurate reading, you can do a cold test , you will see if all the cylinders are the same. First do a cold test, if they are all the same , start the engine warm it up and do a proper test . Leakdown test would be good too.

[hanyou]

did a cold start today with the help of blk180 (thanks mate)

1- 135

2- 130

3- 115

4- 135

5- 130

6- 135

those were the results, couldnt do cylinder 3 again cuz my battery died lol

[wrxhoon]

did a cold start today with the help of blk180 (thanks mate)

1- 135

2- 130

3- 115

4- 135

5- 130

6- 135

those were the results, couldnt do cylinder 3 again cuz my battery died lol

Number 3 looks a bit sus, was it the last one to test ? If yes the battery could have been low and cranking it slower than the others . If it was done in order number 3 is not as healthy as the others. Leakdown test will be more comprehensive . Did the front turbo let go? Did you do a comp test ever before this happened?

[hanyou]

yeah number 3 worries me as well. the cylinders were done in order. unfortunantly i never got around to doing a compression test ever lol this was the first time.

not sure which turbo, let go ill be bringing it to hills motorsport once my turbos arrive. ill get a leakdown test while its there as well.

but yeah i havnt turned on the car since october

[wrxhoon]

yeah number 3 worries me as well. the cylinders were done in order. unfortunantly i never got around to doing a compression test ever lol this was the first time.

not sure which turbo, let go ill be bringing it to hills motorsport once my turbos arrive. ill get a leakdown test while its there as well.

but yeah i havnt turned on the car since october

So you don't really know that a turbo/turbos let go, right ? If you have a cat undo the the cat where it joins the front pipes and check in there . Have you checked the wastegates to make sure they dont stay open?

[hanyou]

im gna go and check my cat right now.

not to sure how to check the wastegates though

edit: dammit i dont have my jack. im pretty sure the turbo let go though as i heard the peices in my cat when it was idling before

[wrxhoon]

im gna go and check my cat right now.

not to sure how to check the wastegates though

edit: dammit i dont have my jack. im pretty sure the turbo let go though as i heard the peices in my cat when it was idling before

The rods should be all the way to the front when the gats are shut . If you have a compressor undo the hose and pump 10 psi or so the rods should move to the rear thn the gates open . If you can blow 10-12 psi you can do that too but you must have strong lungs .. Look in the cat first and if you dont find anything there then look at the gates ... One of the gates open you won't have any boost, any leaks in the system ( blown cooler or pipe ) you wont have vacium ( or maybe very little vacium ).

What kind of turbos are you buying?

[hanyou]

im jus getting the slide hi flow turbos.

not to sure how to check that so i better not do it incase i break it even more lol. but ill check the cat asap.

ive just changed my cooler pipes to a hardpipe kit so that cancels it out and cooler is all good.

[blk180]

Hey mate hope all turns out well for you.

[Brent@kmart]

Before you condem the enigne i would be getting a cylinder leakage test for all you know it could be a valve not seatings find out where the compression is leaking from before you give the engine a full rebuild.. As a mechanic i seen lots of people pay for a full rebuild when its been a valve not seating.. get the cars properly check before condeming the whole engine.. my lil 2 cents add just a thought... but still if u wanna check if it is the compression rings doa wet test as it is called in the industry, this will tell you if it is the rings not sealing..

[gun32gtr]

howd ya go mate,anymore news

[hanyou]

waiting for a mate to lend me his battery recharger and will give it another go. hopefully it will have a better outcome

[gun32gtr]

oh ok well good luck dude

[hanyou]

hey guys just an update, got my car back today!!!

i got my new slide hi flow turbos installed along with xforce dumps & got my hks evc III @ 1bar.

engine was A-OK the rear turbo blew and went into my cat

ill be getting it dyno'd on saturday & will be attending the sau vs. v8 drag day on the 25th, so ill post up the results soon

THANKS AGAIN TO THE GREAT WORK FROM THE GUYS AT NBP (Northern Beaches Performance)!!! and of course all the help from SAU'ers!