MA70 heating problems.

[EldarO]

Hey all,

On thursday i took delivery of my MA70, we had spent four nights, after work, putting the new 7MGTE in...

Now it seems, it has coling problems.

Last night it SEVERELY overheated, a hose from the thermostat blew out, and caused the entire contents of the radiator to be dumped out of that one pipe, and i only noticed since my car started making knocking noises...

So, we cooled the engine down by tipping water on it (i know, cooling it down fast could cause things to crack, but i was desperate), i also cranked the engine over, but didnt start it a few times, in my mind, to prevent the engine siezing.

It took us 4 hours to replace the hose, just because of the location of it, and we also didnt have the correct hose to replace it, being a 90 degree bend, so we got a straight peice of pipe and bent it.

The pipe replaced, we filled up the radiator, cranked the car over, it started, first go, with no complaints, we let the thermostat open, and we filled from there, and closed the radiator cap, i drove it home with no protest from it.

This was about 1am in the morning by this stage... 9:30 am the next day, a friend came over and we went off to supercheap to find a suitable replacment, it ended up being a pipe from a gemini that we cut down to fit, after this was done (about half an hour!) a pin hole in a pipe that we had quicksteel'ed up reopened, and sent a pin stream of water flying about the engine bay.

Drain the water once again, sanded it back this time, and re quicksteel'ed it up with some stuff specially made for holes in metal tanks containing fluids.

Refilled the coolant and off we went.

The reason i didnt know the temp was because my digital guage in the dash doesnt work properly, aswell as the fuel guage, so i grabbed an electrical guage from supercheap and fitted that, it works well, but is in fahrenheit.

Driving it after refilling the coolant the final time, temp sat at 200 fahrenheit, and i gave it a bit of stick, and it slowly rose up to 230, i pulled over, let the thermo fan do its magic, and it dropped to 200 once again, i took off, and repeated a couple of times to get home.

Now, the solution, At the moment there is a heater hose at the back of the engine, which ruptured the first time, and to fix it we just plugged it up, and blocked it off.

What im thinking is, the fact that this hose isnt connected could be causing the whole system to stop flowing properly, so im going to fix both the return and feed pipes tomorrow, im hoping this will stop it.

Before you all say "Its a 7M, BHG" there is no oil in the coolant, and the oil is not cloudy, the water doesnt boil, and it runs better than ever, im debating with a mechanic mate as to whether it has MHG...

The only problem the engine has is the overheating, which i now have under control thanks to the guage, it doesn knock, tap, tick, tock, or have a lumpy idle, its actually running better now than it did before it overheated...

Im going to go ahead and ask the stupid question of whether any other 7MGTE owners have had these symptoms, as i dont beleive its BHG because its not using oil or anything, i think theres a bubble in the block thats causing it to stop flowing, because the radiator feels a fair bit cooler than the actual engine, but that could be because of the turbo...

Ill get those pipes replaced, and ill take it up to a radiator shop on monday for them to check the whole system out, a little bit of money now, to save alot of problems later.

Its an essay, but the last 24 hours have been chock full of action.

Eldar.O.

[Cressida91GLX]

It is not always the case that oil and collent mix up. It might be that the connection between cylinder and collent passage might be blown. And don't forget every one starts by saying it is not BHG but ultimately it is BHG. 7mge will never cause any problem expect when it has got BHG. BHG hahahahhaha sorry

[thechuckster]

checked for other usual suspects?
blocked radiator
dead thermostat
incorrect piping configuration?
air-bubbles (as noted in your original post).

dont forget that overheating can be the trigger of HG or ring problems - not just a symptom.

[JustCallMeOrlando]

All this emptying and filling of the coolant system, have you given it a good bleed? Try sticking a coke bottle with the bottom cut off it in the radiator, and keep topping it up till the bubbles stop coming up while it's running.

[EldarO]

Hey,

Cressida, your advice is about as useful as a kick in the nads.

Chuckster - All the things you listed are fine/not happening.

Nathan, I filled the radiator up, then started the car, let the thermostat open up, topped it up, went and drove it around, then let it cool down and topped it up again.

That said, the problem now seems to have evaporated, with the topping up after it got up to temp, after i filled the radiator up, i took it for a drive, and flexed the turbo's muscles, gave it a fair bit of stick, yet the tempurature didnt move between 200 and 210 degrees fahrenheit, the only time it did was when stationary, which ill attribute to my thermo fans not being hooked up, fixing tomorrow.

The problem seems to have vanished, the car runs, starts and boosts better than ever before, leaving me confused as all hell :/

Eldar.O.

[Cressida91GLX]

Well still it won't hurt to do a compression and T-K test for Gasket. Sorry for being too rude in the early post but I have never seen any complain from 7MGE except heating problem (including my self) for evidance search this forum . Any way best of luck and don't forget to put the coolent in

[Yian]

Eldaro,

Fix the heater lines. Personally, I reckon you shouldn't just block it off. Bypass the heater core and all should be sweet. At least that way the coolant is flowing the way its supposed to (albeit not through the core, but still through the same pipework).

My 7M does creep in temp when its sitting in traffic. Its never once overheated, but has experienced some heat soak on very hot days (turning car off, coming back 5 mins later and its 1 bar above midline... start her up and it drops straight away).

And welcome to the world of 7M ownership Hope you enjoy your stay.

Yian

[EldarO]

Eldaro,

Fix the heater lines. Personally, I reckon you shouldn't just block it off. Bypass the heater core and all should be sweet. At least that way the coolant is flowing the way its supposed to (albeit not through the core, but still through the same pipework).

My 7M does creep in temp when its sitting in traffic. Its never once overheated, but has experienced some heat soak on very hot days (turning car off, coming back 5 mins later and its 1 bar above midline... start her up and it drops straight away).

And welcome to the world of 7M ownership Hope you enjoy your stay.

Yian

Yian,

I fixed the heater hose this morning, i also connected up the thermo fans, im wondering why theres a fan on the front of the 7M and two teeny thermo fans vertically placed on the side of the radiator...?

It does creep up sitting in traffic, and it does heat soak, but its doing these things constantly, not just on hot days.

The car tends to get a bit warm if i boost it a bit, but thats to be expected, if i stop boosting, USUALLY it drops down to normal temp after a few minutes, that said, it didnt drop down the last time i took it for a drive, so im going to wait till its a bit colder, and do what JustCallMeFrank suggested.

Thanks everyone for the advice, Cressida, all good, i know the 7M is world renouned for blowing its headgasket, that said though, it isnt showing any of the signs of it, and it isnt losing either coolant or oil. and now im 90% sure its MHG, either that or an extremely resiliant stocker thats been torqued down to insane levels.

Eldar.O.

[Yian]

Don't worry too much Eldaro. I've got a stocker HG in mine. Torqued down properly + a little more for good measure. Almost 2 years later, a couple of dyno days, many spirited runs, many very VERY hot days and no sign of the 'impending' HG failure.

Saying that though... *touches wood*

[EldarO]

Yian,

Sounds good that the 7M really isnt the fragile peice of equipment that people make it out to be, properly prepared, they seem to be very good

Ive been driving it around today, and it rose a few times to around 210 degrees fahrenheit, which is about 99 degrees celcius, a bit hot under the collar, i think the usual running temp is 90-95?

It didnt rise above that, and drops as soon as the car starts moving, so im not concerned, however i beleive the radiator has a blockage, and will get natrad to acid dip it and clean it up a bit, hopefully it wont cost too much.

A mechanic friend also has a BHG Sniffer, so ill have that checked as soon as he gets it back into his posession.

Take it easy all, thanks for your time

Eldar.O.

[JustCallMeOrlando]

What thermostat you have in there mate?

[hamgatan]

Eldar expect it to heat soak and creep often until about April or so when it starts cooling down climate-wise. February last year mine was creeping a lot to 1 bar over on the temperature.. but that was on a frickin hot day where it was 45 degrees. However come wintertime the car ran good with no overheating until the coolant ran low.. top her up with the good stuff and away she went again..

[EldarO]

What thermostat you have in there mate?

Nathan, as far as i know, which is not much, its all stock, the engine has 111k on it :/

Chris, im expecting heat soak, that said, the heatsoak has informed me that my thermo fans sensor is munted, because it only kicks in when it hits 230 degrees fahrenheit, which is well into the red zone.

ill get a pic up of my temp guage setup so you can all see what im talking about.

Gonna call natrad and organise an appointment for wednesday to get it all checked out.

Cheers everyone for the help

Eldar.O.

[EldarO]

Alright new development.

Im not losing coolant,
Im not losing oil,
The car is not overheating at all anymore,
the only time it runs hotter is when im boosting it, and it drops shortly after i calm down.

I think the engine just needed some time to flush all the p00 out of it, and im fairly sure that heater hose played a big part.

Booked into natrad on wednesday, ill get the cooling system checked, ill post up whatever they say

Eldar.O.

[thechuckster]

Im not losing coolant,
Im not losing oil,
The car is not overheating at all anymore,
the only time it runs hotter is when im boosting it, and it drops shortly after i calm down.

I think the engine just needed some time to flush all the p00 out of it, and im fairly sure that heater hose played a big part.

i'd vote for blocked radiator - it was probably marginal when you got it, and the various incidents following have since filled it with gunk.

Also, check that you have routed the cooling lines for the turbo correctly (unlikely, but possible).