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Discussion Starter #1 (Edited)
My cousin has over 30 yrs experience as a auto mechanic.I told him i have 138k miles on my 90 t-bird & he said "its time for your head gaskets to blow".I change my oil every 3k miles & the motor runs good.Is what he said true ? I dont do my own mechanical work on my car.

Do all or most 90 t-birds blow head gaskets ? I bought my car with 126k miles on it almost 6 yrs ago.I dont know the cars history.I am the 2nd owner in 19 yrs.
 

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It is not a given that your gaskets will blow but it is a known flaw with Ford's 3.8. Whether or not you change them on a good motor is up for debate. The main reason they blow is due to the restrictive exhaust. Replace the downtubes and put on some high-flow catalytic converters and you will likely see another 100k miles out of her.
If you have the time and funds to do the gaskets then maybe you should go ahead, it is a good time to get the engine bay cleaned up and replace any sensors and vacuum lines. If you do, be sure to replace the head bolts with ARP head studs and quality gaskets. (I am partial to the MLS head gaskets.) Whether you change the gaskets or not, you still need to replace the restrictive exhaust.
 

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Discussion Starter #3
What a stupid flaw by ford.Im just not sure if the head gaskets have been replaced prior to me buying the car.I have only had the car for 11k miles & the prev owner had it for 126k miles.I just didnt know then about the head gasket problems.My friend sold his 90 or 91 tbird at 140k miles & no head gasket problem.I was told besides the head gasket problems a 3.8/v-6 is a very good motor.
 

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What seems to help the life to the HGs is to change your antifreeze frequently, like at most every 2 years. Another thing is to watch your temp gauge. If it starts spiking, you'd better find out why or prepare to replace the HGs.

If you decide to replace your HGs, I've got a complete set that I haven't used. I'll be doing the Splitport swap shorly and these gaskets won't work for that.
 

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Motorboatin' SOB, Headlight Cleaning Guru
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The main reason they blow is due to the restrictive exhaust.
yeah, because we all know the exhaust and cooling system on the 3.8s are directly related.

the weak clamping force between the block and heads, having aluminum heads and an iron block, trapped air, and the poor circulation of coolant to the rearmost ports contributes to a blown head gasket. it's almost always the #3 cylinder.

is your bird experiencing symptoms of a gasket that's about to pop?
 

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A large number of them go, I replaced mine in my 89 at around 120k miles.

The gasket wasn't designed for all the movement that takes place due to the different metals for heads and block, and different rate of expansion. Also I think there are hot spots like also posted, BUT that was really primarily in the 3.8 in FWD applications, Windstars and Tauri.

Mine was the middle cylinder on the passenger side that was allowing coolant into the combustion chamber, and combustion gases into cooling system. I don't know if something external caused it to happen, a month prior to getting really bad signs of head gasket failure, the tube to the coolant reservoir came off, and it was during the time of year it is 110+ degrees, so it was just dumping the coolant out, and eventually was a little low, but no big deal.

There really is no way to tell if it is about to happen, once you have any indications it has already happened. But if you catch it early you minimize the problems it causes, like overheating, filling the crankcase with coolant, etc.
 

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It's annoying when it happens to you, but it's not that big of a deal. The engine has lasted over 130k without being opened. So, not too bad overall, right?

The different rates of expansion will always be a problem when using two different metals for head and block. New gasket technology has reduced the problems a lot (MLS gaskets, etc.). But bear in mind your car was built 19 years ago.
 

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It is not a given that your gaskets will blow but it is a known flaw with Ford's 3.8. Whether or not you change them on a good motor is up for debate. The main reason they blow is due to the restrictive exhaust. Replace the downtubes and put on some high-flow catalytic converters and you will likely see another 100k miles out of her.
If you have the time and funds to do the gaskets then maybe you should go ahead, it is a good time to get the engine bay cleaned up and replace any sensors and vacuum lines. If you do, be sure to replace the head bolts with ARP head studs and quality gaskets. (I am partial to the MLS head gaskets.) Whether you change the gaskets or not, you still need to replace the restrictive exhaust.
Tinman, you have helped me and I still appreciate it. I will be in your debt until I can help you. I have a problem with the exhaust flaw idea. Those manifolds were very beefy, they had very large ports that went to the heads. Have you ever seen a pair of 5.0 manifolds? Well, the ports are a lot smaller and the primaries are pinched off. My personal opinion is that it is poor head gasket design. When I fixed my friends 93 cougar the heads only needed a shave of .800. The shop who builds race motors ( I take all my mustang stuff there) said it had to be the gasket or at least the way it was assembled. When I asked him about Ford's flaw of too few head bolts per cylinder he decided to be nice and just suggest ARP bolts.:eek:
 

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Thanks for jumping down my throat, Mike. After researching it more I realized that the exhaust issue is more critical to the Super Coupes, especially when overdriving the SC. On the SC's the first thing to do is replace the 90º bend going into the catalytic converter for preventive maintenance.
I have noticed that the 5.0 T-birds have the same 90º bend. (Both my '93 5.0 parts car and '92 SC have this.) If I ever own another 5.0 or 3.8 that will be one of the first things that I do to it, not only for preventive maintenance but because that bend is just poor flow design for a performance standpoint.
And yes, definitely flush the cooling system at least once a year.
 

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Thanks for jumping down my throat, Mike. After researching it more I realized that the exhaust issue is more critical to the Super Coupes, especially when overdriving the SC. On the SC's the first thing to do is replace the 90º bend going into the catalytic converter for preventive maintenance.
I have noticed that the 5.0 T-birds have the same 90º bend. (Both my '93 5.0 parts car and '92 SC have this.) If I ever own another 5.0 or 3.8 that will be one of the first things that I do to it, not only for preventive maintenance but because that bend is just poor flow design for a performance standpoint.
And yes, definitely flush the cooling system at least once a year.
anytime, derek :) while i agree that the 90 deg. bend is hindering flow, i just dont see how choked exhaust contributes to blowing hg's. my 3.8 has those bends, as well.

when they blew in my 93, i was doing nearly everything i could to keep mine from blowing before they actually went. my temp gauge was going nuts, and i had replaced the tstat and burped the cooling system of air frequently. my 95 is doing well, then again the previous owner had the dealer ($$) change them out. all i have now is a mysterious coolant leak.
 

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anytime, derek :) while i agree that the 90 deg. bend is hindering flow, i just dont see how choked exhaust contributes to blowing hg's....
Again, this is mostly a problem on SC's with an OD pulley on it but with any car, if you plug the exhaust the air leaving the chamber will have no where to go. The pressure will increase (especially if you drive hard) until the air forces its way through into the coolant passages. This is more likely to happen if (as you mentioned before) if you don't flush the coolant system on a regular basis.
 
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