Mechanic to help diagnose overheating?

[thomas.f]

Hey all,

I have a 96 gts which every now and then decides to overheat.

To give a little detail, if I where to drive from Wellington city to Kapiti the car would drive perfectly and build boost the whole way. When I come off and stop at lights or drive in a 50k area the temp will very quickly rise.

I have been fighting this for a while now and have done the following:

Full coolant flush and had the radiator cleaned out.
New thermostat.
Burped coolant many times.

My thought is that it could be a head gasket but I am not seeing any common signs of a head gasket that has given up.
My local mechanic did offer to dig around but did admit that he was not the best person for it having not worked on any mid engine cars.

That all being said, does anyone have a recommendations for a clued up mechanic who can outright tell me what's wrong so I can work towards fixing / getting it fixed. ( In the Wellington region).

Thanks!

[GDII]

Have you tried using the chemical test for head gasket leaks?

Also if you take off the coolant filler cap when the car is cold then start it, does it bubble?

[Benckj]

Sounds like a rad fan issue. Have you tried to pull the temp sensor plug to see if fans both go?

[GDII]

Sounds like a rad fan issue. Have you tried to pull the temp sensor plug to see if fans both go?

That does sound like a very possible problem. Which sensor electrical plug is best pulled? The one on the radiator itself?

[mknz]

Sounds like a rad fan issue. Have you tried to pull the temp sensor plug to see if fans both go?

This, your mechanic would have picked this up (hopefully). For the most part people can work on them since they're just an ends swapped FF. The only thing I can think of that they need to know is how to bleed it properly.

[thomas.f]

Have you tried using the chemical test for head gasket leaks?

Also if you take off the coolant filler cap when the car is cold then start it, does it bubble?

I have run run the car from cold with coolant filler cap off nothing bubbles or overflows at all, I haven't tried the chemical test kits would it be worth picking one up? I have heard mixed opinions?

[thomas.f]

Sounds like a rad fan issue. Have you tried to pull the temp sensor plug to see if fans both go?

Yeah I have pulled the plug fro the sensors and both fans come on full, when idling the fans do come on and off as expected once up to temp.

[GDII]

Sounds like a rad fan issue. Have you tried to pull the temp sensor plug to see if fans both go?

Yeah I have pulled the plug fro the sensors and both fans come on full, when idling the fans do come on and off as expected once up to temp.

Does it run while the temp rises above normal? Only one is for the radiator while the other for the AC system.
Does the radiator and main pipes, especially the right hand side get hot?

[thomas.f]

Sounds like a rad fan issue. Have you tried to pull the temp sensor plug to see if fans both go?

Yeah I have pulled the plug fro the sensors and both fans come on full, when idling the fans do come on and off as expected once up to temp.

Does it run while the temp rises above normal? Only one is for the radiator while the other for the AC system.
Does the radiator and main pipes, especially the right hand side get hot?

From memory when the car is overheating the radiator fans dont come on, I will need to check that again. I did say sensors in previous reply, I ment the one sensor on the radiator half way up right hand side.

The right hand side radiator return pipes are hot when the car has been run for 10+ mins.

[tw2]

Thermostat stuck? Look at a mechanical compression test and leak down if you want to know the exact health of the HG, rings and valves.

[ClanFever]

TMS Racing is the go to in Welly for performance cars - Justin and co have looked at my Mr2 and others before so they can help if required

Your car is showing the same symptoms as mine - cracked block was ultimately the diagnosis - you are however most likely running the gen 3 3sgte not the gen 2, I don't know if these are as likely to crack

[thomas.f]

The other thing I should mention is that a previous owner has bypassed the heater. The send and return lines have been looped. Not sure why this was done, could have been a previous owner trying to fix the overheating issue? This is something I would like to fix at some point also.

Could this be related due to a lower ammount of coolant in the loop?

[GDII]

If the heater hoses are looped it's possibly because the hard lines rom the engine to the heater core were leaking. This is very common on these cars. The loop, depending on how it's been done could create an air lock but as the heater can be shut off normally the loop doesn't always have coolant running through it. Do you have any photos of how it's been done?

[thomas.f]

If the heater hoses are looped it's possibly because the hard lines rom the engine to the heater core were leaking. This is very common on these cars. The loop, depending on how it's been done could create an air lock but as the heater can be shut off normally the loop doesn't always have coolant running through it. Do you have any photos of how it's been done?

My thoughts exactly, there is a set of extra rubber hoses from the heater core back but they where cut and looped in the engine bay. I also dont have photos but can get some tomorrow.

[GDII]

If the heater hoses are looped it's possibly because the hard lines rom the engine to the heater core were leaking. This is very common on these cars. The loop, depending on how it's been done could create an air lock but as the heater can be shut off normally the loop doesn't always have coolant running through it. Do you have any photos of how it's been done?

My thoughts exactly, there is a set of extra rubber hoses from the heater core back but they where cut and looped in the engine bay. I also dont have photos but can get some tomorrow.

That sounds like it was leaking. Most likely on the bracket of the left pipe at the back. Fuel tank out that fix is. Done it on mine.