When I got my 1990 Thunderbird SC 12 years ago it had only 21,000 miles. Now later with years of easy driving it now has 80,000 miles. My question is that I hear around 75K the head gasket fails. Is it inevitable that mine will fail soon, since it has never been replaced.
SC Head Gasket Failure
- Thread starter aspedt2
- Start date
The answer to that question may depend more on how well maintained it is, what level of sanity is applied to any mods, and if you beat on it like a rented mule.
Are there hints something is wrong? Do you have any other reasons to tear down the top end? Are you planning on certain mods?
Are there hints something is wrong? Do you have any other reasons to tear down the top end? Are you planning on certain mods?
I'd guess if they haven't gone by now, you've got at the least a few more years at the rate you've been accruing miles. I'd not assume it's a given they will need attention any time soon.
potshotscott
Registered User
I think head gasket survival has much to do with the operating quality and efficiency of the cooling system and how hard you drive the car. The only HG I've had fail was on my N/A 3.8 93 LX that I beat up as a kid. I flushed the cooling system without paying any attention to the fill/purge bolt on the top of the engine. A day or two later the HG popped. Pretty sure I had an air bubble in the loop because I didn't service the cooling system correctly.
I've personally replaced blown head gaskets on SCs anywhere from 120K to 175K. I also had an 89 XR7, with a late model blower and 10% pulley that I regularly beat the snot out of for almost 2 years, and at 168K, it spun a rod bearing, but the head gaskets never failed on that car. So in short, at only 80K, you are probably Ok for a while.
slowpoke
Registered User
yes, with this engine your head gasket will fail. when is the true question. after about 80k your at risk. some have lasted longer than 200k. mine took a poop at about 180k. its not if its when. when mine went it did give some warning. for about a month before it started losing coolant but i couldnt find any leaks. it wasnt blowing any smoke but it was somehow burning it off. then while driving at 0400, 70mph on the interstate on my way to report for duty it popped. still ran fine but noticed the temp gauge shoot up. as i started to pull over the engine then died and it was done.
SuperCoupeDave
Registered User
The 2 SC's I have had in the past both blew at 150k. Both within a few thousand miles of each other.
1FSTBRD
Registered User
You're right about cooling system efficiency, I think. Plus, I wonder sometimes, how many times someone may have put in regular fuel instead of premium (before we had bought our cars), and how frequently they changed the coolant.
blake90cougar90
Registered User
I have a 1990 xr7 5 speed I just got and it has 175,000, not sure if all orginal or not, I see that the valve cover gaskets been changed but not sure how to check HG to see if they been changed, but I beat on it several days a week and running good but I changed all the fluids including sc fluid but I the other question I have let’s say someone before me change the HG will they blow again?
Drive more, worry less. My 90 auto has 172K miles. Never did anything but regular service. Original plug wires, and a set of plugs at 60K. Here's the deal, get some temperature in the engine, before it see's any boost. Also, when changing the coolant, get all the air out, before driving it. Even with the bleeder spitting coolant, it's not enough. Turn your heater to vent, and if still cool, you still have air.
fstcoup
SCCoA Member
I believe the best way to prevent the head gasket issue is to change the exhaust. The early cars have a restriction as the exhaust changes from a downward direction to then go to the back of the car, a ninety degree turn which slows the exhaust and creates back pressure which in turn pushes on the heads.
Your local laws may dictate what you may or may not do and there are numerous ways to go.
Your local laws may dictate what you may or may not do and there are numerous ways to go.
blake90cougar90
Registered User
that's what my grandpa did to his 89 SC he was telling me that there on the driver side where it comes off the manifold it 90 right into the cat and his mechanic fix his but that has been a few years ago and with the cat theft rate sky rocketed the amount of people/exhaust shops that will do it is like 0.00000000076 I guess I could cut them off take it to them and have the weld a pipe in place so tech there just fixing the broken part idk if that would even work but id like to fix the exhaust!! and for some reason when I got the car it had red/ pink ish antifreeze in it??