No bubbles. But it could still be the head gasket between two adjacent cylinders. I will be doing a compression test on all 6 cylinders over the next week when I have time.
If you mean the radiator cap then I did replace that. It’s holding pressure nicely.
The fans do work, but they are coming on a 224F instead of 215F.
When they do come on it slows the heating but doesn’t reverse the heating (cool the motor down).
Thanks.
Confirmed.
Interesting.
This overheating is occurring at idle.
Are you saying the transmission could get that hot sitting at idle?
Since the vehicle is high mileage but also and mostly because it sat for 4 years, I’m suspecting a head gasket issue between two adjacent cylinders.
I think it’s possible that rust may have invaded the head gasket and possibly eaten through that narrow strip between two cylinders. I have no water in the oil, not losing coolant and no known leaks a head gasket failure in that case would be between two side by side cylinders. I read that this can also cause overheating by keeping those two cylinders from fully cooling from the fresh intake fuel charge and being subjected to constant hot exhaust gases.
With that in mind I am considering doing a compression test on all 6 cylinders.
If it turns out to be a head gasket I’ll just move up my scheduled engine pull and rebuild date a little sooner than I had planned. No sense in pulling the heads and not going all the way.
The plan was to rebuild the engine any way. I was just trying to move it to a different location for that but I can do it where it is if necessary. (I sure wish I could find a 3.8 to replace this 3.3L)
What are your thoughts on that?
The compression test seems like a good idea; however I doubt a head gasket problem is causing the overheating. My guess, compression will test ok, and you either have a clogged radiator or there’s something wrong with the fan’s ability to move air, for example maybe they aren’t blowing at the correct speed, radiator or AC condenser air flow clogged, etc. The symptoms are pretty consistent with a cooling system that isn’t running at the correct pressure, but it appears you’ve already eliminated that as a possibility. Another idea, maybe the mixture is too lean. Any indications of that, fuel trim test?
If you had one of those IR temperature laser-measuring gadgets you could quite easily get an estimate of the temperature of the transmission fluid going into and out of the radiator.
It would be so good if you’re right (no head gasket issue).
I have a new radiator arriving tomorrow. Before I install it I’ll do a compression test just to make sure there’s no obvious problem.
I pretty much ruled out the fans since they do blow at high speed, there’s no obstruction going through the condenser or radiator and they are definitely blowing the correct direction.
Could be a defective radiator.
The OBD2 readings seem to point to an ok mixture reading looking at the fuel trim…Short term looks normal and long term looks good. Also if it was running lean (or rich) it would probably throw a fault code.
I haven’t heard any knocking, even when it was hot.
I have a laser thermometer but I also have a thermal camera. If the transmission cooler was hot I would have easily spotted it. It s
In case someone with a similar vehicle finds this later…
I completed the compression test and while one cylinder was near or at the service limit (cold) all were still at or close enough to the serviceable point that this was not the issue in this case.
The compression on the one low cylinder will likely rise if checked at operating temperature.
Throttle wide open, 7 cranks, engine at ambient temp (92F)
(8) Compression should not be less than (689kPa)
100 psi and not vary more than 25 percent from cylinder to cylinder.
Cyl 2 - 160psi
Cyl 4 - 170psi
Cyl 6 - 125psi
Cyl 1 - 162psi
Cyl 3 - 165psi
Cyl 5 - 143psi
So all that really remains is the radiator (as suggested above) and or possibly a collapsing hose since the overheating occurred WITH both fans going at high speed.
Thanks for all the assists and suggestions. It really helps.
If you haven’t already done so, suggest to replace both radiator hoses with new when you replace the radiator. Don’t recall, has a test been done for exhaust gasses in the coolant? If not, suggest to do that before replacing the radiator.
Thanks George.
Both upper and lower hoses are new replacements.
I just checked the compression and nothing bad enough to cause this problem was evident.
I did the exhaust gasses in coolant test a number of years ago but I may need to do it again.
In spite of all my efforts, the over heating persists. Tomorrow my new radiator arrives because the new one I received last week was not the correct one (I had to re-order).
Today I discovered that both heater core hoses remain cool even with the engine warned up and only cool air comes from the heater. This is probably a big clue. Unless I’m mistaken it indicates a nearly totally clogging of the heater core (unlikely) or a lack of water circulation (probable). Even though the water pump is new and thermostat is new and installed as described in the FSM. I cannot find any evidence the belt is slipping. The water pump seems to be spinning at full engine speed.
Yesterday I disconnected both the upper and lower radiator hoses and ran the garden hose into the radiator cap hole while sealing it as best as I could and watched the water flow freely out of the lower radiator hose fitting which goes TO the water pump. Then I closed off that hole and watched the radiator fill and all the water came out the top radiator hose fitting. So it at least seems the radiator is not restricting the flow from this simple test.
I’m just not sure yet where the problem is. Could be radiator…Could be thermostat…Could be a persistent air bubble in the cooling system yet the FSM does not outline any special procedures for refilling the cooling system except “fill it to the top”
Another big clue is that the car does not cool down while moving. It stays at the same temp or continues to creep upwards slowly. Occasionally it seems to drop a degree or two but then it doesn’t… Once moving I expect temps to drop quickly…but that doesn’t happen. I’m going to completely remove the thermostat and try that just to rule out the thermostat as a restriction of any kind.
Today I flushed out the cooling system completely, added two bottle of Prestone cooling system flush and will run it for about two hours then drain and refill in case old rust and sludge is causing the problem.
That said, the top radiator hose does get very hot after the thermostat opens.
The top half of the radiator gets very hot. The bottom half quite warm but not near as hot.
Bizzare situation and very annoying.
I have to admit it has me baffled and frustrated.
Cooling system may be clogged w/debris. When you drain the current radiator, drain the coolant into a bucket, then pour it into another bucket with a screen over it, to see how much debris comes out of the radiator. Also, after you remove the current radiator, turn it upside down and reverse flush it with a garden hose using same technique.
The way I test for obstructed flow and water pump problems on my truck & Corolla --done as part of a coolant replacement job – is remove the top hose at the radiator, figure out a way to extend that hose into a big leak-proof container (like a 32 gallon trash can), open the top of the radiator so I can see the level. Idling the engine f rom a cold start, at first no coolant will come out, but as engine warms up thermostat will open and coolant will start coming out. I’ll keep radiator filled using garden hose. Eventually – takes 5 to 15 minutes of idling — warm-to-hot coolant will start pouring out of that top hose with a really strong stream, similar to a fully-on garden hose. Note: There is some risk of engine damage involved w/this test, too much cold water from garden hose could potentially crack engine block. Only do this if you accept taking the risk in other words. Never experienced that problem in many years of doing this myself though.
Thanks.
I’m really reeling over this at this point. Feel like I’m getting nowhere fast.
At least at this forum there is patience and my thread hasn’t been locked and I haven’t been ridiculed by the moderator for still having the problem. 
I won’t give up. Not a chance.
Thanks for ANY and ALL suggestions.
You may still have get that problem … lol … a few years ago it took me several months to rebuild my truck’s carburettor, and I took on some ridicule here for taking so long. But it all turned out ok, truck running well, & I was later awarded the “taking the longest time in forum history to rebuild a carb” award … lol
I feel your pain my friend
Good job on the carb 
Have you ever put the thermostat in a pan of water on the stove and made sure it opens at the correct temperature and the correct amount? I do that as a routine procedure whenever I replace a thermostat, both old one and new one. There’s usually obvious problems with the old one, and sometimes the new one fails right out of the box.
I didn’t do that George.
I just bought and installed a new one and nothing changed.
The upper radiator hose does get very hot about the time the thermostat is due to open, maybe a bit earlier than expected. It’s a 180F thermostat that seems to begin opening at about 160F.
Removed thermostat today to see what would happen.
It seemed I was just beginning to get some heat from the vents (on high heat) but it suddenly went back to cool air coming out. That makes absolutely no sense.
This is not a fan related problem. It over heats just as persistently when moving.
Hard to believe air could still be in the system after all the burping and topping I’ve done.
I didn’t drive the car after taking the thermostat out but I still think it HAS to be the radiator.
If changing the radiator makes no difference I am totally at a loss.
I need some way to actually test the water circulation in the system to see if the pump is actually moving the water sufficiently. It’s a brand new good name water pump.
I forget, did you replace the water pump?
Is that an 83 / 84 GTI in your avatar?
If so, I had one back in the day that I installed a Callaway turbo system on.
Blue interior. Sunroof. Loved that car.
That was in the mid 80’s.
That little thing was so fast for it’s time. Had a blast!
It was on par with the 5.0 Mustangs and even the 911’s at the time (up to about 120 ish.)
Oh…yes, put in a new pump
Did you flush heater core during your efforts? Wondering if all coolant hoses are flowing freely now
Yes, black with red interior, had it '83-'96. Most fun car I’ve owned, even with its 90 hp.
