OVERHEATING & Absolutely Clueless What To Do Help Needed

[coney]

Where do i start

Some of you may know i've had a full engine rebuild but having only been out in the car just the once since having it back in june last year & overheated that time its been waiting inline at GR-Performance a local Subaru & Mitsubishi Specialist but having spoken to them today things are looking a little grim to say the least!

They said what i already had an idea about, That was the fans (fan only one could be fitted due to the close proximity of the front turbo) behined the intercooler are only engaged when the car is static, but when my mate took the car to GR he had to pull over a total of 6 times (this was on a 12 degree fahrenheit day baring in mind) from here to there it's only 20 minutes away is horrendous!
What they said to me today was shattering! the are going to do all the usual checks but couldn't put it would on the dyno if all the checks came back without any significant problems & they would do more damage obviously if it's overheating when the car is moving the fan on the dyno wouldn't make a blind bit of difference.

Then came the salt in the wound, Tey said if it is something internally they don't specialize in these V6 engines & would need to find a specialist who would be able to diagnose the problem even a complete strip down.

I'm afraid if it does need a complete strip down that will be the end of my VR4 days & will be selling it for parts.

If any of you guys can help bring what the problem is to light you will believe how grateful i would be!

Regards

Neal

[Nick Mann]

The fan control on the standard car is weird, they run at various voltages depending on several inputs to the ecu including temperatures and if air con is engaged. Could you wire your fan to be permanently spinning? You give the impression that it doesn't overheat when idling?

[swinks]

Seconded to what Nick says.
I believe you have standalone ecu. Well, why not use fan control as on/off status, you can hook one to ignition ACC and this is sorted. Or you can hook one to aftermarket controller based on temperature in upper hose (it's own temp sensor control, once temp reach 71C it will trigger fans to switch on), I have such controller somewhere here in drawers from old good vr4 times.
Another idea is just to use so called "half radiator" from Evo market. These rads are especially designed for Evos running big turbo setup where space between manifold and turbo in front is very limited. So they use thick "half rad" with single aftermarket fan. That is efficient for drag racing Evos so should be for yourself. Saying that because I'm afraid single fan for thick regular size radiator may not be efficient enough, you are leaving half of rad area not cooled at all.

[giblet]

Would it not be better to have the car shipped to Eurospec? The chaps there all well versed with the VR4 so would be better placed to diagnose any issues and rectify them.

[Confused]

Only having a single fan shouldn't cause a problem - the fan is only really used when the car is stationary, and the coolant is up to temperature.

The standard ECU does not just switch the fan on or off, it uses one of the two coolant temperature sensors in the top of the thermostat housing to vary the fan speed based on coolant temperature - it comes on slowly at about 90 degrees, and reaches full speed when the coolant is approaching about 110 degrees. If either the coolant temperature sensor, or the "hedgehog" transistor pack which is usually bolted to the back of the fan housing.

It also switches the fans on/off based on the status of the air conditioning.


When driving (especially at light throttle and a steady speed), there will be sufficient air flowing through the radiator to not require the fans to engage, which should keep the engine cool, PROVIDING that the coolant system itself is functioning correctly.


So - first off, provide us with some more details.

Are you using the standard ECU? If so, have you hooked up EvoScan (even with a cheap £10 VAG KKL cable) to check that the coolant temperature sensor is functioning correctly? This is an ~£8 part which could solve all your issues if it is not functioning correctly!

Do you still have the original fan "hedgehog" controller? And if so, which of the two fans did you disconnect from it? The hard-wired one, or the one that plugs in to it?


If you don't have the standard ECU, what wiring changes have been made to control the fan?

Are you sure that the coolant system itself is functioning correctly, without any air locks or blockages? Have you replaced the thermostat? Have you replaced the radiator cap with a new, genuine part? Does your heater inside the car work?

[apeman69]

Is it the same company that did the engine rebuild? Have the obvious things like a blocked radiator or pipe been checked or, as said above, is the temp reading on the gauge correct (is it really overheating or does it just think it's overheating)?
It's always possible that the radiator or a pipe was plugged with something for convenience during the engine rebuild and somebody forgot to remove the obstruction.
Is it overheating when idling for a long time or only overheating under load?

[coney]

The fan control on the standard car is weird, they run at various voltages depending on several inputs to the ecu including temperatures and if air con is engaged. Could you wire your fan to be permanently spinning? You give the impression that it doesn't overheat when idling?

My problem is Nick i can't physically do anything to the car which is whats getting to the most, so i don't know how the fan is being controlled,when the car is fired up you can hear the fan engaging, On the first initial outing it only overheated when we were waiting for 4 cars to go through the petrol station till we got to fill mine up,it was only when we pulled out it judderd and cut out as i said before.
All i can do Nick is pass the word on or try to find out how the fan setup to work with the ecu.
Sorry if i gave that impression about the fan.

[coney]

Seconded to what Nick says.
I believe you have standalone ecu. Well, why not use fan control as on/off status, you can hook one to ignition ACC and this is sorted. Or you can hook one to aftermarket controller based on temperature in upper hose (it's own temp sensor control, once temp reach 71C it will trigger fans to switch on), I have such controller somewhere here in drawers from old good vr4 times.
Another idea is just to use so called "half radiator" from Evo market. These rads are especially designed for Evos running big turbo setup where space between manifold and turbo in front is very limited. So they use thick "half rad" with single aftermarket fan. That is efficient for drag racing Evos so should be for yourself. Saying that because I'm afraid single fan for thick regular size radiator may not be efficient enough, you are leaving half of rad area not cooled at all.

Swinks yes Vipec v44 i believe,if i'm honesty with 90% of what you said has gone over my head i suppose it's just simply because i can't get my head under bonnet,its all well & good reading but trying to absorb information when your not looking at what your actually reading plus the fact after all these years things still don't sink in due to damaging my frontal lobe all adds up to a completely ****e memory to the point where i can at times forget what i'm saying mid convertion. I've heard people tell me that a certain person has called me just plain thick & play on the brain damage from the volvo hitting me,that kinda hurt & pissed me off at the same time.

[coney]

Would it not be better to have the car shipped to Eurospec? The chaps there all well versed with the VR4 so would be better placed to diagnose any issues and rectify them.

Giblet it boils down to money at the end of the day mate,if i knew it could all be sorted out for say £1000 i'd be arranging it now!

[coney]

Only having a single fan shouldn't cause a problem - the fan is only really used when the car is stationary, and the coolant is up to temperature.

The standard ECU does not just switch the fan on or off, it uses one of the two coolant temperature sensors in the top of the thermostat housing to vary the fan speed based on coolant temperature - it comes on slowly at about 90 degrees, and reaches full speed when the coolant is approaching about 110 degrees. If either the coolant temperature sensor, or the "hedgehog" transistor pack which is usually bolted to the back of the fan housing.

It also switches the fans on/off based on the status of the air conditioning.


When driving (especially at light throttle and a steady speed), there will be sufficient air flowing through the radiator to not require the fans to engage, which should keep the engine cool, PROVIDING that the coolant system itself is functioning correctly.


So - first off, provide us with some more details.

Are you using the standard ECU? If so, have you hooked up EvoScan (even with a cheap £10 VAG KKL cable) to check that the coolant temperature sensor is functioning correctly? This is an ~£8 part which could solve all your issues if it is not functioning correctly!

Do you still have the original fan "hedgehog" controller? And if so, which of the two fans did you disconnect from it? The hard-wired one, or the one that plugs in to it?


If you don't have the standard ECU, what wiring changes have been made to control the fan?

Are you sure that the coolant system itself is functioning correctly, without any air locks or blockages? Have you replaced the thermostat? Have you replaced the radiator cap with a new, genuine part? Does your heater inside the car work?

Confused its a vipec v44 if i remember righly,i didn't do the work myself i'm paralyzed from the neck down hence why i had all the work done for me,i don't know what work was done with the wiring of the fans,intercooler ect.

[coney]

Is it the same company that did the engine rebuild? Have the obvious things like a blocked radiator or pipe been checked or, as said above, is the temp reading on the gauge correct (is it really overheating or does it just think it's overheating)?
It's always possible that the radiator or a pipe was plugged with something for convenience during the engine rebuild and somebody forgot to remove the obstruction.
Is it overheating when idling for a long time or only overheating under load?

Apeman Not a company the same person,apparently when the car was dropped off it had covered 2000 miles without a glitch yet the first time i went out in it it overheats but i'm not going into who's a fault all i will say it wasn't anything me or my carer,dad or mate did.
So as far as i'm aware if the car had done the 2000 miles prior to been dropped off the back of the flatback there shouldn't have been any blockages what so ever.

The Gauge Sensor is another sore subject as far as i'm concerned! the person who did all the work knew the sensor could have been iffy but said i was rushing him for time but over a full year isn't rushing in my mind unless i'm highly weird & time goes faster than i realise!

To be honest Apeman both.

[coney]

Is it the same company that did the engine rebuild? Have the obvious things like a blocked radiator or pipe been checked or, as said above, is the temp reading on the gauge correct (is it really overheating or does it just think it's overheating)?
It's always possible that the radiator or a pipe was plugged with something for convenience during the engine rebuild and somebody forgot to remove the obstruction.
Is it overheating when idling for a long time or only overheating under load?

Apeman Not a company the same person,apparently when the car was dropped off it had covered 2000 miles without a glitch yet the first time i went out in it it overheats but i'm not going into who's a fault all i will say it wasn't anything me or my carer,dad or mate did.
So as far as i'm aware if the car had done the 2000 miles prior to been dropped off the back of the flatback there shouldn't have been any blockages what so ever.

The Gauge Sensor is another sore subject as far as i'm concerned! the person who did all the work knew the sensor could have been iffy but said i was rushing him for time but over a full year isn't rushing in my mind unless i'm highly weird & time goes faster than i realise!

To be honest Apeman both.

[Louis]

I think you need a short list of what needs done to fix basics and then take it to a tuner, who knows Vipec, to sort it out.
Reading from other posts I don't think it is an internal engine issue, more of a tuning issue, combined with possibly a couple of sensors.
At the end of the day it will cost money at a tuners to diagnose and program.
It may just need dumbing down! for daily use, a tuner could possibly fit a piggy back ecu like E manage so it is not so complicated.
But like any car, a garage or tuner will have to diagnose by running engine (rolling road) and reading ecu to see what is happening.
If you point them in the right direction it will be fixable, but fine tuning takes time and time is money.
On a side note Eurospec sell and tune Vipec units.

[Grid]

I know you have a trust issue with the person that made the overhaul. However he can probably fix all issues the quickest. Technically speaking. On human terms - I don't know where you two left off.

[coney]

I think you need a short list of what needs done to fix basics and then take it to a tuner, who knows Vipec, to sort it out.
Reading from other posts I don't think it is an internal engine issue, more of a tuning issue, combined with possibly a couple of sensors.
At the end of the day it will cost money at a tuners to diagnose and program.
It may just need dumbing down! for daily use, a tuner could possibly fit a piggy back ecu like E manage so it is not so complicated.
But like any car, a garage or tuner will have to diagnose by running engine (rolling road) and reading ecu to see what is happening.
If you point them in the right direction it will be fixable, but fine tuning takes time and time is money.
On a side note Eurospec sell and tune Vipec units.

Louis how can i possibly come up with a short list of what needs to be done when i i haven't got the foggiest idea of what exactly is causing the issues & what makes it harder is not being able to do any work myself , the only thing i can do is try to explain what happened when it cut out.? I can't find anybody who knows the vipec's ECU'S well isonly Euro-spec, i sent Ben an email yesterday night so i should imagine he will be getting back to me on monday hopefully.

I uploaded a few videos on youtube which i'll add links to in an hour or so.

[coney]

A few videos of it trying star!

https://www.youtube.com/watch?v=t6BUxHf7Af0

https://www.youtube.com/watch?v=4rl0x9boqOU

https://www.youtube.com/watch?v=3ptvEXjpg6o

https://www.youtube.com/watch?v=1vPBxugPCD0

[Davezj]

this might sound an odd quiestion, but does the cooling system have a thermostat fittted.

without it the cooling system will not operate correctly the coolant will tend to just flow round and round the engine without passing through the radiator. the radiator will get hot due to convection of hot coolant but it will not be cooling the engine.

just a thought.

[swinks]

this might sound an odd quiestion, but does the cooling system have a thermostat fittted.

without it the cooling system will not operate correctly the coolant will tend to just flow round and round the engine without passing through the radiator. the radiator will get hot due to convection of hot coolant but it will not be cooling the engine.

just a thought.

Not the case Dave, flow of coolant is forced by water pump. Lack of thermostat will actually drop temp of coolant quite dramatically, especially under driving conditions.

[swinks]

IIRC, ViPec standalone ecu is now rebranded as "Link G4".
Indigo GT seems to specialize in these ecu's. And excellent tunning place as well.

[apeman69]

I'd be looking at your engine temp sensor and wiring from this to the Vipec. Maybe the sensor has failed or wiring has been dislodged somehow when it was transported to you. Perhaps the tuning isn't right for the temp sensor but this would have shown up in the initial 2000 miles unless your tuner is telling porkies. I'm not clear if you had the car for these 2000 miles or the tuner.
If the tuning is questionable and the ECU's getting spurious readings from temp sensor this could cause you problems starting (which I've seen from your videos) and running.
I couldn't hear much in the videos but I saw you showing a couple of dangly wires. Surely these could have been dislodged by drivers' feet.
I'd expect whoever did the work to backtrack over the fitment as a matter of urgency and not put you into a year-long queue. Maybe it's time to get tough with him?