Overheating, poor idle.... Head Gasket?

[5150DSM]

Allright, I've been searching and testing and testing and changing parts and searching and testing... I'm at a loss.

Went to the track, car overheated on the way back, I kept it out of the red with the heater and limped home. Blown heater line, coolant everywhere. Replace the line, clean up, refill the coolant, no problem. Car still runs hot, not overheating but hot, burp it out, better. The following week, car starts running hot again. Do some simple testing and find that the thermostat is bad(cold top hose, hot bottom). Replace the thermostat, refill the coolant, burp the system repeatedly, car still runs hot. Ok, so the fans stopped working, replace the fan switch, check the relay(good) and the fans still don't work. Pulled the plug and found it all melted to shit, fan wiring melted and shorted burning up the plug. Shield all the wires, hardwire the slims to my A/C switch, voila, fans work. Go for a drive, still running hot. And now it's idling like shit, 10-12hg when previously it was a solid 18hg.

Compression test showed 185 across the board, no mixing of oil and coolant, no smoke from the exhaust but everytime I check the coolant level it has dropped 1/2-1qt so it seems to be using coolant. New head, freshly machined block, composite gasket(copper sprayed) and ARP studs. Other than the shit idle(and the overheating), the car runs fantastic.

I have two theories, one I blew my head gasket in a way that's unique to me or two, my ECU is in the process of taking a shit on me. I'm already pretty sure that the fan control circuit is cooked in the ECU and I'm wondering what else. I'll pull it tomorrow and check the board. In the mean-time, I'm looking for some opinions and/or suggestions, things I missed, other things to test, alternate theories, whatever you guys can come up with.

Thanks in advance to any and all who can help.

Tony-5150DSM

 

[96' Eclipse GS]

When was the last timing belt job done? It is possible that the water pump is giving up.

 

[5150DSM]

When was the last timing belt job done? It is possible that the water pump is giving up.

Timing belt and water pump were replaced approximately 700 miles ago when I built the motor. The pump is definately flowing but I have noticed what appears to be cavitation (small stream of bubbles) in the coolant neck while filling the system.

 

[96' Eclipse GS]

Drop a (combustion leak tester) & see what you get. Worse case you indeed have a BHG or you don't, then you can go a different path. You will want to try the tester 3 or 4 times, because they sometimes not at all accurate.

 

[5150DSM]

Drop a (combustion leak tester) & see what you get. Worse case you indeed have a BHG or you don't, then you can go a different path. You will want to try the tester 3 or 4 times, because they sometimes not at all accurate.

Is that the blue fluid in the tubes contraption? I've not used one before, primarily due to lack of need; but, I have read that the accuracy is questionable.

I guess if it keeps showing up brown over and again, I can rely on that to some degree.

 

[96' Eclipse GS]

Lisle Tools 75500 Combustion Leak Detector on eBay!

I have used it before & looks to be promising. You can pick one up locally I'm sure.

# 75500
Line Code: LIS.

 

[5150DSM]

It was a head gasket. Borrowed a combustion leak tester (thanks 96' Eclipse GS), ran the test twice, went from a friendly blue to piss yellow after a pump or two. Oh well, tear it down again.

I spoke with Nate at MAP today and he basically talked me out of the SCE Titan copper gasket, stating that he felt it was too maitenance intensive for a DD. His reasoning was sound from what I understand and I appreciated his advice. He felt that for my application and goals that the Felpro Permatorque would be the best choice. After some thought, that is probably the route I will take. Does anyone have any input about the Felpro Permatorque? Thoughts, critiques, advice?

 

[honda_burner]

Its what I plan on using for my build. I already have it set aside ready to get smooshed under the head.

 

[96' Eclipse GS]

It was a head gasket. Borrowed a combustion leak tester (thanks 96' Eclipse GS), ran the test twice, went from a friendly blue to piss yellow after a pump or two. Oh well, tear it down again.

I spoke with Nate at MAP today and he basically talked me out of the SCE Titan copper gasket, stating that he felt it was too maitenance intensive for a DD. His reasoning was sound from what I understand and I appreciated his advice. He felt that for my application and goals that the Felpro Permatorque would be the best choice. After some thought, that is probably the route I will take. Does anyone have any input about the Felpro Permatorque? Thoughts, critiques, advice?

Oh, well. At least WE figured out the problem yet again, thanks to the small things! Great to hear that you are going to rebuild it and not give in. On a side note, that you asked again. That would be more than what you need, with the first link I have listed.

STM: COMETIC HEAD GASKET | 90-99 DSM | 4G63

Now, unless I am mistaken, you want to try this HG that I linked to below? That is "a little" too much for me.

Fel-Pro PermaTorque MLS Head Gasket for Mitsubishi 4G63 90-99 [1153-1] - $219.00 : Jay Racing

Which ever one you choose "GOOD LUCK" on the rebuild & let us know how it turns out...

 

[5150DSM]

Thanks. I've never really had any luck with the Cometics. They always seem to have sealing issues when I use them; could be the prep but "once bitten twice shy". Yeah the Felpro is expensive but if it's the last head gasket I put on this motor then the cost justifies itself.

 

[huafist]

Oh, well. At least WE figured out the problem yet again, thanks to the small things! Great to hear that you are going to rebuild it and not give in. On a side note, that you asked again. That would be more than what you need, with the first link I have listed.

STM: COMETIC HEAD GASKET | 90-99 DSM | 4G63

Now, unless I am mistaken, you want to try this HG that I linked to below? That is "a little" too much for me.

Fel-Pro PermaTorque MLS Head Gasket for Mitsubishi 4G63 90-99 [1153-1] - $219.00 : Jay Racing

Which ever one you choose "GOOD LUCK" on the rebuild & let us know how it turns out...

$219.00?!?!?! ExtremePSI sells the same gasket for $185. I'd bet shipping is less too.