TromboneChat

I've recounted my woes with various cars here over the years.

The latest was the Volvo, overheating with a blown head gasket.  We're pretty sure of the diagnosis, the upper hose gets pressurized tight as a steel pipe, must be a good amount of exhaust gas getting into the coolant. 

The Chevy, which has one payment left! overheated on my way to bone choir Saturday.  I had it towed in.  The diagnosis is water pump, but I'm skeptical that's all.

We went car shopping this weekend and bought a low mileage VW Passat. It's the newest car I've had in decades and there's great relief in having something reliable, but we can't afford two new cars, need to fix at least one of the other two for short local trips.

So we come to my question.  I got the broken stud out and put the Volvo back together sans thermostat.  It runs and doesn't overheat at least in the neighborhood, but it does build up pressure in the hoses.  The last car I had with a head gasket problem eventually blew a hose while I was driving, not pleasant. 

Coworkers swear by that head gasket sealer stuff, Blue Devil or Barsleak, but my web research says absolutely a waste of time, doesn't work and makes things worse.   Any opinions?  Anybody tried it? 

I've had BarsLeak work, but it might not for an exhaust leak.

Depending on the car's overall condition I'd pull the head, check the cylinders carefully, do a valve job, and put it back together.

It makes no sense to do all that work and not do the valves while it's apart.

Also, the head probably warped and will need resurfacing.  Which came first, the overheating or the exhaust leak?  They're related in multiple ways.  Gotta fix everything, or you'll be throwing money away.

We've had that 91 Volvo quite a few years.  My daughter used it for college and had some massive overheating then, due to a water pump failure.  My theory, the head warped back then, but not too badly.  Volvos are famous for running okay with minor head gasket failures.  But it's been several years and it eventually let go. 

It's not worth paying anyone to fix.  If I had a warm place to work it might not be a bad winter project.  This thing is not as complicated as modern cars. 

I wish there were a way to periodically vent pressure buildup. 

Cars are a massive drain on funds. Older cars are even more of a drain.

I'd suggest swapping out your cars for something super cheap and efficient, like a new or nearly new mitsubishi mirage. I got mine brand new for $12k last year. The thing gets 58mpg on long trips, but has been averaging 45-50 day to day. Any issues, I just bring it in too the dealer and use the warranty. I'm gonna trade it in next year for the 2019 model.

I imagine that buying it used would be significantly less than that, and you would save a ton on gas. Old cars aren't as great a deal as they seem.

Quote from: timothy42b on Oct 31, 2017, 05:38AM...

I wish there were a way to periodically vent pressure buildup. 

Back in the Bad Old Days we used to have vented radiator caps, but the operating pressure on those systems is lower than today.

A pressure relief valve is still the temporary answer to your problem, but you will have to figure out proper operating pressure and the pressure when it's in need of a relief.

Yes, and I don't just want to let it push all the coolant out, that's just as bad.

Hm, if paying someone to repair the HG isn't worth the cost, and you also don't have a warm place to DIY the work, then I'd suggest tossing it up on craigslist and disclosing the issue. Could probably get it sold for a few hundred to low couple thousands depending on model/miles/condition/etc.

If you live remotely close to racetracks it might be attractive for the low-cost endurance racing leagues (24 hours of lemons, chumpcar, luckydog racing, etc) as-is. Old Volvos are super popular there because they run forever even with overheating engines. They're pretty fast too, given the competition is for least horrible $500 car.

As far as fixing it goes....I don't have any cheap quick fixes. Either do what Doug suggested or pay a shop to do the same, or swap a known-good engine in the current one's place (aka, the lemons fix). There isn't much else to do.

QuoteThe Chevy, which has one payment left! overheated on my way to bone choir Saturday.  I had it towed in.  The diagnosis is water pump, but I'm skeptical that's all.
If it's between fixing that or the Volvo with the blown head gasket, fix the Chevy.

Cheaper to do. Easier to do if you have a warm garage to do it in and have the tools.

QuoteThe Chevy, which has one payment left! overheated on my way to bone choir Saturday.  I had it towed in.  The diagnosis is water pump, but I'm skeptical that's all.
If it's between fixing that or the Volvo with the blown head gasket, fix the Chevy.

Cheaper to do. Easier to do if you have a warm garage to do it in and have the tools.