Compression Test Results

[gstbuford]

Well I purchased a JDM 6 bolt from osakajdmmotors.com. First thing I did was drain the oil and drop the pan to have a looked at everything. To my surprise, the oil looked milky WTF After seeing that I decided to do a compression test. 50 across the board. Any thoughts? I am thinking popped head gasket but I know it could be other things. Im pretty disappointed considering I payed 1500 bucks for the motor and their return policy consist of a 50% re-stocking fee. O well you live you learn I guess. Any thoughts? Thanks guys.



-Stephen

 

[BogusSVO]

have you called and asked them what they will do for you since it sounds like they shipped you a bad engine?
do you have any idea how long the engine has been out?
dose the engine spinn over proper?

 

[Mindslayer]

You may need to turn the crank over up to 7 times to get an correct reading.

 

[gstbuford]

well today i changed out the head gasket and re timed it and the compression is reading as follows

1st cylinder- 145
2nd cylinder- 130
3rd cylinder- 130
4th cylinder- 90

The battery we were using was gone by the time we got to the 4th cylinder. It was dark and just decided to let it charge over night and try again tomorrow. The funny thing is that the headgasket wasnt the problem. The old one was in good condition.

 

[nick]

Try to pot some oil in the plug hole in see if the compression comes up

 

[Jeff99GS]

The Compression is going to be low if the engine is cold. You are supposed to do a comp test when the engine is at operating temp and with the Throttle blocked OPEN. Did you remember to open the throttle?

 

[gstbuford]

i put some oil in the cylinder that held 90 psi and it jumped to 150. and yes i made sure the throttle was open. any ideas?

 

[lacroixdp]

Run the engine for a while then take a compression test. I've had engines that have been sitting for long periods give me odd readings. Running them for a while usually cleared up the readings.

 

[gstbuford]

i guess ill just have to cross my fingers

 

[91 TSi GP]

hopefully you dont have any bent valves or anything of that nature..

 

[force_feed]

Told ya so Steven!!!!!!!!

 

[Jeff99GS]

Dude if I did a comp test on my brand new engine while it was cold I would probably get around 90.
Your pistons and Rings expand slightly when they are hot. This will give them a tighter fit and obviously higher compression. If all of you cylinders are the same or pretty close, then you'll be fine trust me man.

I had 90 psi compression while the engine was WARM last summer in my old 7 bolt and I still ran a 13.8 like that.

 

[Fabian]

I dunno about it being CRAZY low like that when its cold. I did cold compression tests on my 1g right after I did the rebuild and it read 160 across the board and factory says it should be 164.

 

[Levesque]

advice never buy from them again ... there from home and there horrible.

 

[force_feed]

This is exactly what gstbuford looked like when he was reading the compression guage

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[Jeff99GS]

Compression will drop 15 psi when cold. Im not saying his compression is going to jump to 160 when its warm...but it WILL go up surely.

 

[BogusSVO]

hopefully its just light tarish/rust not letting the rings/valves seat....MAYBE a little run time will get it all to seat back in.

Is this a "brand new" rebuild or a used engine?

 

[force_feed]

its a used JDM motor with a new headgasket.

 

[BogusSVO]

with a little luck it is just a small piece of trash between the valve and seat, a gasket flake or piece of carbon.

 

[gstbuford]

This is exactly what gstbuford looked like when he was reading the compression guage

You must be logged in to view this image or video.

thats an understatement

o jon that flywheel will be here tommorow