overheating is back

[phines]

I let the local garage track down the problem, so they took the valve covers off. I don't know how easy or difficult that is. This is where the broken head bolt was:



The bolt broke off right above the thread, so the valve cover and gravity was the only thing keeping the top of the bolt in there. If you have the same problem, you won't be able to fix it yourself. There aren't any bolt extractors that can reach it from the top side of the engine.

And yes, you could have had this problem all winter. I had the problem for several years before I finally figured out what it was and fixed it. I had to be very careful driving on warm days and it was never a problem on cold days unless I was towing a heavily loaded trailer.

[zadam123]

I let the local garage track down the problem, so they took the valve covers off. I don't know how easy or difficult that is. This is where the broken head bolt was:



The bolt broke off right above the thread, so the valve cover and gravity was the only thing keeping the top of the bolt in there. If you have the same problem, you won't be able to fix it yourself. There aren't any bolt extractors that can reach it from the top side of the engine.

And yes, you could have had this problem all winter. I had the problem for several years before I finally figured out what it was and fixed it. I had to be very careful driving on warm days and it was never a problem on cold days unless I was towing a heavily loaded trailer.

that sounds like exactaly what my problem is, thanks for the responce. I looked in the manual and am not going to even atttempt this job ,now i just have to find a mechanic to try listing to me to check this out. Just curious how much should i be charged to check this out?

[zadam123]

just one more question, i took off the radiator cap and let the car run for about 10 minutes and noticed that the antifreeze never went down just rose to the rim and slowly spilt out (little bit) shouldnt the level have went down if the thermostat opened?

[IndianaVX]

just one more question, i took off the radiator cap and let the car run for about 10 minutes and noticed that the antifreeze never went down just rose to the rim and slowly spilt out (little bit) shouldnt the level have went down if the thermostat opened?

It should, if the thermostat is working as IT should..... And I would think this bolt repair..... There's alot of stuff that's gotta come off to get to it, price will be accordingly. Sorry this happened, good luck!

[phines]

The way the technician explained the problem to me was exhaust from the combustion chamber was making its way into the radiator fluid (we could clearly see the path across the head gasket too) and this was over-pressurizing the coolant system causing the flow to be much slower or completely stopped (almost like having two pumps pumping in opposite directions).

I never tried running the VX with the radiator cap off so I don't know what to tell you there.

A decent garage should be able to determine if the head bolt is broken off in an hour or two, so check their hourly rates. Tell them not to loosen any of the head bolts, just look for a broken one. Once loosened, you have to replace them with new bolts. You might be able to get away with just replacing the one bolt, assuming they can get the broken piece out.

[phines]

The thermostat is way simpler/cheaper to replace so do that first if you haven't already. But I'm guessing the bolt problem would cause the same slow overflow you saw with the radiator cap off.

[Bob Barker]

Again, don't forget you can burp the system to get an air pocket out. IF there is air in it, the thermostat will still open, but it won't circulate because the water pump blades are essentially spinning in an air pocket. Find some ramps, or some tall jacks, get the front all the way up as high and safe as you can and find the high spot in the system. Run the car until it's warm and you are sure the t-stat should be opening and open up the high spot, it may be the cap since it's in the middle of the radiator unlike a lot of other cars. It may be a bolt I can't find. But it's free and worth a shot. If you see a lot of bubbles coming up when you open the cap and the truck heats up then make sure you have some extra fluids on hand to put back in there so another air bubble doesn't get in.

Worth a freebee shot.

[Y33TREKker]

...Run the car until it's warm and you are sure the t-stat should be opening and open up the high spot, it may be the cap since it's in the middle of the radiator unlike a lot of other cars. It may be a bolt I can't find. But it's free and worth a shot. If you see a lot of bubbles coming up when you open the cap and the truck heats up then make sure you have some extra fluids on hand to put back in there so another air bubble doesn't get in.

Worth a freebee shot.

My car actually has a second radiator type cap incorporated into the intake casting at the designated high-spot that makes burping the system very easy. I looked in our manual and didn't see anything specified as far as any designated "high spots" in our cooling system though.

All the manual really says for our systems is that re-filling the system at a slow rate once any work is completed is the best way to prevent air pockets from forming.

[Bob Barker]

The Mach 1 I sold had a cross over pipe between the heads that had a really hard to remove bolt. May be something like that with our trucks.

[VXobsession]

Sounds to me like your head gasket. Last year before I bought my VX, the previous owner spent almost $3,000 getting the heads fixed. The mechanic that worked on it apparently didn't machine the heads down properly nor did he tighten the bolts as much as he should've.....my baby has just now gotten out of the shop getting the heads fixed again. Luckily, I paid for parts and that's it. My mechanic is one of my best friends. I didn't know my head gasket was blown, there were no symptoms, except for a little overheating, under the same conditions you've experienced. There is something called a "block tester"...costs about $45 from NAPA. Follow the instructions and you can find out if there is combustion leaking into your antifreeze. THAT will happen before antifreeze leaks into your oil. Once antifreeze leaks into your oil, your on your way to bigger and more expensive repairs. So catch it early! You can buy this block tester and check it yourself or let a mechanic charge you $300 to do the same thing. At least if you do it yourself, you'll know what your mechanic needs to fix instead of them charging you to look at it, test it, tell you what's wrong, and then finally charge you for working on it. They might "find" a lot wrong with it, charge you for it, and you'll still have the same problems because they didn't fix the correct thing in the first place.

[zadam123]

ok he told me he did a compression test and it was good, he said that my thermostat was a aftermarket one and was the wrong temp (i think he said it was a 170) he said i need the 190 OEM one and is in the prosess of changing it , I told him it would seem that the 170 should make run cooler but he said aftermarket ones are no good and may not open all the way.well see tommorrow

as far as the block tester is that like a compression test?

[tom4bren]

I've been fighting a similar battle with my 03 Eclipse for 2 years now. I've finally gotten it to where although it runs hot in stop-n-go traffic, it doesn't overheat.

What I've done so far:

1. Shop replaced temp sensor. They replaced the wrong one though. They replaced the one for the temp guage instead of the one that turns the fan on/off.

2. I replaced the correct temp sensor but it didn't help.

3. I replaced the water pump (was told that it could be that the vanes on the water pump were eroded to the point that it wasn't moving enough coolant). That didn't fix the problem either & the old pump looked fine. BTW, I replaced the timing belt while I was in there.

4. I replaced the thermostat twice (once with aftermarket & once with OEM). That didn't fix the problem either. I'm running without a thermostat right now.

5. I tried repeatedly to burp the system with no success. I was told that the system could get a bubble behind the thermostat which would cause it to not open. I even drilled a hole through one of the thermostats to allow any bubbles to seap through.

6. Replaced the relay that turns the fan on/off. It was dead & now I can drive it without the fear of overheating (even though it still runs hot according to the temp guage).

Eventually I'll put the thermostat back in & probably replace both temp sensors again but there's no rush. The only problem I have running it without the thermostat is that I get a CEL about once a week during the winter indicating that the engine is running too cool.

I know the vehicles are very different but maybe you can glean something from my trials.

[rsteinmetz70112]

Reading the last post something occurred to me. Have you checked to see if it actually running hot? Is it simply a gauge error?

Different situation but I once had an English car when for some unexplained reason once the car warmed up the temp gauge went to the peg, if the headlights were on. If you turned the dash lights down the gauge went down as well. The engine was not running hot.

[tom4bren]

Reading the last post something occurred to me. Have you checked to see if it actually running hot? Is it simply a gauge error?

Yah, I thought of that too. That's why I plan on replacing the sensors again eventually. Too many other pots on the fire to worry about it right now though.

[MSHardeman]

Do you have a ScanGauge, or some other OBDII reader that you can hook up to the car (either of you)? That way you could get a temp reading off the ScanGauge and bypass the dash gauge to see if it is reading correctly or not.