Another thermostat housing question??

chadder1313

chadder1313

Registered User
I know im gonna get bashed for this but, if the thermostat housing is leaking the least bit will it throw the coolant system all out of whack. Ive been noticing it would drip like once every minute and i do plan on fixing this today. But my question is would this slight leak be the cause of excess pressure in the coolant? My coolant system is working fine under normal driving conditions but as soon as you get WOT for a few seconds it seems to build pressure and pump coolant to the overfill tank. I've been leaning towards a HG's but it runs perfect when not raping on it.
 
Well first I wouldn't be having forceful sex with the car...:eek:

chadder1313 said:
but it runs perfect when not raping on it.
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j/k, I would address the housing leak first. Then try having more forceful sex with it and if you still have a problem it very well could be an early sign of hg failure.

Is you oil and coolant mixing?

Keith
 
LOL!! But all is well with the oil and the car runs exceptionally well. Mid 12's:D

Its just when you beat on it for a brief moment the temperature wants to rise. When the car does this the temp. will rise and almost instantly come back down to normal. If it was HG's were going wouldn't i have excess pressure in the system all the time, instead of only when under WOT.
 
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Thats very possible, as my signature stats my car is UNTUNED. I know it needs tuned and maybe because of it not being tuned we may have an issue. Does this sound right?? Is it possible?
 
Well if nothing is mixing/leaking in the oil/coolant, its doubtful its the headgaskets.

Fix your housing leak, and see what happens, make sure you bleed the system out too etc.

How high does the temp. actually get to?

Does it run perfect or is it detonating? Got colder plugs?

You said you were running 12's so im sure you have most of your ducks in a row.

Keith

edit: noticed you said it was untuned...could be an issue...
 
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I do have colder plugs and id like to think i have most everything under control. Its like it just started doing this after i put the MPX on.
 
chadder1313 said:
I do have colder plugs and id like to think i have most everything under control. Its like it just started doing this after i put the MPX on.
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Are you using MLS gaskets or Composite ?

When I first switched over to MLS gaskets along with a set of ported heads, I had the same thing happening whenever on the dyno or on the track. I drove the car like that for about 8 months. Finally pulled the heads and found they were not properly surfaced in one area that had some pitting on the deck. Resurfaced the heads and installed a fresh set of gaskets...problem solved.

What you are describing sounds like a leaking head gasket, but it could also be a cracked head.

David
 
chadder1313 said:
LOL!! But all is well with the oil and the car runs exceptionally well. Mid 12's:D

Its just when you beat on it for a brief moment the temperature wants to rise. When the car does this the temp. will rise and almost instantly come back down to normal. If it was HG's were going wouldn't i have excess pressure in the system all the time, instead of only when under WOT.
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almost does sound like he's talking about a woman lol
 
Ha!! Dave, when i did the head gaskets a couple years back i had them resurfaced, ported, and when installed i used ARP head studs. For years no problems up until now. I guess she didn't like sitting over the winter. I guess what I'm gonna do is see if she holds up at the track on Sunday and if she gets to hot ill pull the heads. If not, back to square one.
 
chadder1313 said:
Ha!! Dave, when i did the head gaskets a couple years back i had them resurfaced, ported, and when installed i used ARP head studs. For years no problems up until now. I guess she didn't like sitting over the winter. I guess what I'm gonna do is see if she holds up at the track on Sunday and if she gets to hot ill pull the heads. If not, back to square one.
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MLS or Composite gaskets ? I'm asking because once the composite gaskets start leaking they don't stop, but an MLS gasket can leak under a big load then seal back up under normal driving conditions.

David
 
chadder1313 said:
Its the one SCP sells with their upper engine gasket set. I'm not actually sure.
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If they are the gaskets that come in the Felpro upper gasket set for an SC, they are Felpro blue stripe composite gaskets. Those either leak or they don't. I'm wondering if you have a small leak that is always happening and you just don't notice it under normal driving conditions. Easy way to tell is to look at the over flow tank and see if air bubbles are coming up from the bottom of the tank while it's idling. Goose the throttle and it should get worse if a gasket is leaking.

Before doing anything, I'd put a new radiator cap on.

David
 
Generating heat under load in conjunction with pressure in the cooling system is leaking headgaskets because of detonation, no discussion is really necessary. Don't blow it up, change the gaskets now and get a tune or at least a chip. You have too much ignition timing.
 
10-4 I heard that!! You have an email. So MLS head gaskets for a 98 Mustang? Also do you think it will blow if i make a few passes down the track? I mean if worst comes to worst i do have a spare engine on the stand.
 
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Glad I read this post, I had a very similar thing happen last fall at my last trip to the track. During my second pass my overflow tank filled up completely and blew the lid open and coolant went every where. I let the car cool down and drained the overflow tank and made another pass. It filled up again but my coolant temp never went over 200 deg. I thought it was just the rad cap failing so I drove it home and it was fine. Now I think I may have popped a head gasket?? I' going to do a pressure test on the system but not sure if I want to put on my new blower and more boost and start beating it with a possibly blown HG. Should I just change em.
Thanks
Drew
 
Mine was doing the same thing 2 years ago, pushing coolant into the overflow after a boosted run. I changed headgaskets and has never happened since, I also did not find a visible leak path in the gaskets when removed.
 
Its very strange. I don't get it. I'm just gonna do the head gaskets and get Dave to tune the car. Back to square one!
 
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