Low compression numbers

[chicagoavenger]

Well guys I have been battling overheating issues and while I wait for the man Kristen to bring over his radiator I went ahead and did a compression test. Here are the numbers as follows and I made sure the car was warmed, throttle plate fully open and all spark plugs out. I also had a charger on the battery for fully cranking power.


Dry Wet
#4-100 #4-108
#3-100 #3-105
#2-100 #2-105
#1-90 #1-100

I never did a test before the head install so I can't compare numbers but she seems like she has plenty of power but what do you guys think? Service limit is at 121 or 122 but I'm not sure if altitude will affect those numbers. Now my other issue is with the overheating still with the slimline fan at idle or driving or at night with no thermostat in the temps will still climb. I thought with the thermostat out she should never reach operating temps but she has no problems going beyond that. I'm going to check the torque specs on the arp's again just to start doing process of elimination. I plan on doing a leakdown just to see where I'm losing my compression but I hope it's not the damn headgasket not sealing because she won't stop overheating. Any suggestions or ideas guys? Also my boost gauge reads 10-12 at vac. I'm pretty close to just say screw it and get the Wess Hess upgrade and call it a day
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Shant

 

[95blackGsTurbo]

Is your timing off? Those are insanely low and numbers and since putting oil in there didn't seal the rings I would either guess your timing somehow jumped and you aren't noticing it or your rings are just gone. The headgasket wouldn't go out in all four cylinders unless you really messed something up.

 

[chicagoavenger]

Timing is perfect car has 145K is it possible the rings are really worn?

 

[95blackGsTurbo]

Yeah. Have any problem blowing your dipstick out?

 

[chicagoavenger]

No problems with dipstick either and I did the test 2x with some other people to verify I was doing it correctly. Also the compression tester we used is reading correct because we tested it on another vehicle

 

[chicagoavenger]

Well good news kinda, We just did a leakdown test and yes it is leaking out of the cylinders and a little out of the intake/exhuast valves. BUT not 1 single bubble or air or anything out of the coolant. I know this sounds dumb but that was my biggest concern do to my overheating issues. The only thing left to test is swap out radiators and hopefully she will be all good. As far as the compression numbers go, hell I'm gonna keep going until she has nothing left then it's build time. So let me ask you this, if I swap out radiators and she still over heats then what could it be? Just heads up we installed a new water pump when we did the headgasket and timing components.

 

[1sick91tsi]

if the car runs fine and is just over hearting try and fix that first. the compression is low but i had a 90 psi motor for d.d. that went 12s all day seemed fine until one day i decided to do a compression test and almost pooped myself. in any case your compression didnt raise much from putting oil in i would say its mostly the valves leaking. and if the coolant system didnt pressurize then the head gasket should still be in good shape.

 

[chicagoavenger]

if the car runs fine and is just over hearting try and fix that first. the compression is low but i had a 90 psi motor for d.d. that went 12s all day seemed fine until one day i decided to do a compression test and almost pooped myself. in any case your compression didnt raise much from putting oil in i would say its mostly the valves leaking. and if the coolant system didnt pressurize then the head gasket should still be in good shape.

I'm about to swap out the radiator here in about 60 min so we shall see what happens so I'll post back results here in a few.