jonnydclark

This is my sister's 98 3.4 with 228k+ on the clock but in excellent condition and she has owned it since 80K miles.

15k miles ago I put in timing belt, water pump, t-stat plus a bunch more unrelated. All Toyota parts

1 month ago it over heated while towing on a 95 degree day and radiator was dry.

No water in the oil. No apparent leak outside or from heater coil. No smell from the exhaust or a lot of steam. Coolant does disappear.

It continues to over heat, often creating a high pressure jet sound coming from the reservoir overflow tube.

Changed the thermostat
changed the radiator cap
pressure checked the coolant system (this was done by a shop, I am assuming they let it cool down before doing the pressure check but they could not find any leaks)

She continues to drive it just putting coolant in it regularly.

Today a shop put in a new T-stat and radiator cap claiming that the cap was the wrong one and that it had allowed the water to go out prematurely and once overheated probably damaged the t-stat. (they promised to refund if it didn't fix the problem so she will be going back there first thing in the am)
They also did a coolant flush and new fluid etc but only 25 miles later it over heated again. This time, the gauge went high but there was still fluid in the reservoir (prior the reservoir was going dry and she would put more fluid in it whenever it got hot).

Has anybody seen similar and do you suspect head gasket / head issues causing compression to go into the water jacket? If so, how do you find it (which head) if it only does it hot?

Any chance it would just be the radiator?

She really does not want to get it rid of it as it is black Limited with hood scoop and in great condition. Probably not worth rebuilding the top end to her though if she has to pay someone to do it. I'm in SC she lives in AR.

She and the truck are currently in GA and need to drive back to AR tomorrow or ASAP.

Thanks for any help / experience you can share.

rworegon

If it's a HG, it really makes no sense to only do one side while it is all torn down.
No leaks or cracks in the overflow tank? What condition is the radiator? Fins clean?

Have they performed a cylinder leak down test?

jonnydclark

No. Do you think they would need to do the test with it hot?

Radiator looks good.

I guess doing both head gaskets would be smart but it would be nice to know which side to examen for a cracked head etc.

Wondering what it is worth in current condition if she finds a new vehicle. I don't have time to drive 12 hrs round trip and rebuild the top end but it is in too nice of a shape to throw it out.

rworegon

Don't believe it's done hot.

Has the head/block interface been closely inspected with a mechanics mirror and a good light for coolant crust?

Both heads would have to go to the machine shop for pressure testing.

Does it have a rear heater? Are those lines rusted out and leaking coolant? Thry would have to be leaking at a good pace for it to loose enough to overheat in 25 minutes though.

The pressurized sounds tilt towards HG.

jonnydclark

So today the shop did a "block check" with some sort of dye that would show compression gasses and it does not appear to be positive. (Based on their judgement, unfortunately I'm still 6 hours away)

They told her that she needed a fan clutch and, though I and another mechanic back in AR argued against it, put swapped the clutch. It may have helped a little but not really.

Although they said that the radiator flowed fine when they did the flush I can't think of much else that it could be. Any theories on where the fluid is going? Does the leak have to be pretty bad for it to be seen in the exhaust as steam or smelled? Can't see evidence of a leak making it to the ground or around the radiator anywhere. I'm pretty sure if there was ANY getting into the oil it would be evident by now as she has been driving and refilling the fluid for weeks now.

UKrunner

Its a head gasket. I'm fixing mine right now with exactly the same symptoms. Mine has leaked at #3 which is center cylinder on the passenger side. I'm doing all the labour annd having a shop do both heads. I will have about $1000 in to the repair which includes t belt, idlers, water pump and t stat as well as a gasket set, head bolts, plugs, oil and filter.

jonnydclark

Turned out to be a clogged radiator. Not sure why the radiator flush didn't reveal this but after trying everything else we changed the radiator and it hasn't over heated in the last 15k miles.