lart951

I need some advice my car has blown the head gasket 3 times in the past 2 years,the last two within 2 months, I had installed a wide ring head gasket, my car is not heavily modified; autothority maf kit, stage II intercooler, Adj. fuel reg.,Lindsey boost enhancer, hard pipes and racing blow off valve, and test pipe. The head was rectified and resurfaced. Last time the gasket failed (1-6-03)I didn't even run hard on my car. Please help if you have any Ideas what may be going on.

David Floyd

I would say get that baby on a dyno to check your air/fuel ratio. I would bet you are way lean.

lart951

Thanks for the help, my mechanic has checked on the mixture and said that it was ok, my oxygen sensor is unplugged as well, but I will follow your advice and get it dynoed.

nine-44

Was it blown out, burnt through, or just leaking?

lart951

First and second time it was blown out, this time it just started leaking coolant and blowing white smoke through the exhaust. when cold as soon as it heats up stops.

white 944 turbo

I agree with all the above but one thing you may want to do is have that head inspected because if it got too hot the first time it let go it may be warped. This is obviously not visible to the naked eye so have it checked out. If it is you will have constant head gasket failures. I would also recommend o-ringing the head.

lart951

I'll be taking the head apart tomorrow,the head being warped, is something that has also been in the back of my head, also I was thinking it may be that my thermostat gauge is not working properly and the car may be running too hot thus warping the head. but I'm
just wondering.
Thank you for your input White 944.

dmoffitt

good luck, pulling the head isn't as scary/annoying/time consuming as i thought it would be - hope you find the solution -- could it be possible that the autothority chips that i _assume_ (correct me if i'm wrong) come with the MAF kit could be leaning out too much on top? i recal someone posting a while ago about that, and quite a few ppl loosing headgaskets that way...

lart951

Yes indeed I have the autothority chips, I'm thinking of changing them or I could use the "digital mass flow kit" from lindsey racing which by-pass the chips program. I'm so frustrated with this, I guest I just have to wait until I open the head and try to find out what's going on.
Thanks Dmoffitt

lart951

Yes I do have the autothority chips, and I would like to change them or install the Lindsey Racing "Digital mass flow kit" which by-pass the chips program, I had the same setup in my previuos 951 and I never experience any problems with the head, and it had over 140k miles. My current 951 has only 96k and it's driving me nuts.

dmoffitt

yeah, from what i've heard the digital mass flow kit basically tricks the chips so you can fine tune mixtures - like, if the chip is giving it too much fuel, i think you'd basically be massaging the signal to make it think it was getting a little less air (and then, the chip would reduce fuel, bringing your mixture back in check).

what concerns me about ALL of this, is, are you going to get to a point where you're basically "clipping" the signal? kinda like, runnign 109% duty cycle on an injector, you're really at 100 -- ie, can you reach a point that your tweaking the MAF signal up or down so much that it can no longer be adjusted, and hence you still couldnt' bring the mixture down to idea (um, 12.5-ish?). i guess you'd have to call in one of the experts (danno/travis, mike/dave lindsey, etc) to answer that one, my knowledge of the factory DME/KRL is that they are annoying-to-fit-back-in-the-car boxes with lotsa wires and one vac. line

if, however, you want just plain chips, i think hands down the GURU chip seems to be the best (at least, public opinion says so here, and from talking to dan, wow he knows his stuff). if you want to adjust the signal going to the DME, you've got a ton of choices, from the GURU map kit, to Huntley's maf / arc combo, to the digital maf from Lindsey Racing... and others no doubt that i am not aware of. I in fact recently spent a little while doing comparison shopping (confusing, but your best bet is to call the people who make each one and just listen).

good luck getting her back on the street!!

lart951

Thanks Dmoffitt, may be I put the autothority MAF kit for sale, and get me one the guru MAF & chips.
By the way white 944 refer to o-ringing the head, do you know what he means by that?

dmoffitt

see a recently posted thread about o-rings, but my understanding is that a groove is cut into the head to allow for the installation of a small metal ring (wire?) to help create an even harder/tighter(/better?) seal between the head and block, thus allowing you to run higher boost.

btw, do you have any aftermarket gauges? are you running stock boost? it could be if you're pegging your boost gauge (factory) that you've got a cut wastegate line (or, if you aren't the 1st owner, some REALLY dumb people disconnect them on purpose).... i think that's what caused me to burn a valve (the car was running at 24-25 psi and i had no way of knowing 'til i put the gauges in, i thought i was hitting 15-16 and hence at the max of "2 bar" on the factory in-dash gauge.... oops! <img border="0" title="" alt="[Frown]" src="frown.gif" />

lart951

Today the head was removed, the gasket was damaged by #2 cylinder, and I think I know what was causing the problem. Believe it or not I found one of the cycling valve lines damaged. This would explain the head gasket been blown several times. Thanks dmoffitt it was your suggestion to check the wastegate line that
gave me the idea to check all my vaccum lines. Thanks a Lot!

Bill

lart951,

I just pulled my head this weekend. Water in #4 cylinder. DOH!

Like you, I found a vacuum line disconnected.

I spoke to Powerhaus and I now plan to get one of their ported heads that are o-ringed, wide fire head gasket and an extrude honed intake. They claim a 27 hp increase. You just have to turn a bad situation into a good one.

And you can bet that I will clamp or tie wrap every damn hose that I can find!