Coolant temps around 240 after four corners at COTA.

[Lienrocs]

Hey everyone. I’m at a loss. Ive got massive coolant temp issues. I’m seeing temps go from 200 to 230 in half a lap at COTA (80 degrees ambient temp). I’ve replaced the thermostat, water pump (or gt4) and put a new do88 radiator in it and am running VP Stay Frosty (I’ve also run oe, distilled water and water wetter) and nothing I’ve done has fixed it. I even removed the ac condenser to see if that helped. I can’t even complete a full lap. I’ve done a chemical check to see if the head gasket is intact and it came back good to go. (I’ll do a compression test to verify). I’m at a total loss. Any and all feedback is welcome.

[kolosy]

hate to keep throwing parts at it given that you've done a fair bit already, but .. oil cooler?

[Lienrocs]

All the other coolers are done. Litchfield oil cooler and do88 PS and DCT.

[mikerunt]

Chasing is e9x M3 temps was always such a frustrating experience for me. Sorry your dealing with it - wish I had some more useful advice!

Possibly air in the system? Did you use the pressure fill method?

[Lienrocs]

I’ve tried both. Normal bleed procedure and used a vacuum bleeder.

[tdott]

Possible faulty tstat?

If it doesn't open up fully, temps will raise like that when there isn't enough flow for the heavy load.

You can take it out, and put it in a bowl of boiling water and watch it open.

[Lienrocs]

I just put a new one in about a week ago.

[dogbone]

Not sure what modding has been done to your car, but something else to check for is to look for air gaps in the path to the radiator. If the air coming in through the air vents in the bumper has the ability to escape through gaps, instead of being forced through the radiator, it will absolutely go around. If the air doesn’t go through a radiator, then the radiator is not being utilized and the liquid isn’t cooled.

So, look at the air path to a particular cooler. If you can identify any gaps for air to escape and not go through the radiator, then do what you can to seal the gaps. I had to do that.

[Lienrocs]

Originally Posted by dogbone

Not sure what modding has been done to your car, but something else to check for is to look for air gaps in the path to the radiator. If the air coming in through the air vents in the bumper has the ability to escape through gaps, instead of being forced through the radiator, it will absolutely go around. If the air doesn’t go through a radiator, then the radiator is not being utilized and the liquid isn’t cooled.

So, look at the air path to a particular cooler. If you can identify any gaps for air to escape and not go through the radiator, then do what you can to seal the gaps. I had to do that.

I’ll look into it. It’s all stock shrouding and seals but I’ll give it all a once over!

[amg6975]

From experience the DO88 radiator does not seal very well around the rad supports. I used some expanding crack filler foam from Home Depot with a lot of success.

That doesn't really explain those kind of temperature issues, 240 for water temp is pretty extreme. I'd look at faulty [new] thermostat, install issue, blocked hose/rad, something is pretty wrong.

Two other things to check are the fan, and that all the undertrays are intact and in good shape?

[Lienrocs]

Originally Posted by amg6975

From experience the DO88 radiator does not seal very well around the rad supports. I used some expanding crack filler foam from Home Depot with a lot of success.

That doesn't really explain those kind of temperature issues, 240 for water temp is pretty extreme. I'd look at faulty [new] thermostat, install issue, blocked hose/rad, something is pretty wrong.

Two other things to check are the fan, and that all the undertrays are intact and in good shape?

I’ll check all the seals. I’m running a Zebulon splitter so the under tray doesn’t fit but the ducitng on the core support as well as oil cooler duct are all in place. I’ll check for gaps though.

All in the last 100 miles:
New radiator, thermostat, water pump, upper and lower hoses and the fan kicks on no problem.

Driving down the freeway in 80 degree weather water temps are sitting at 180 (thermostat temps). The car gets to temp fine and it’s a brand new T stat.

[tdott]

I know you mention brand new parts, but I just wanted to point out it's still possible you got a faulty part. Sucks, but possible. I know a few have complained about do88 quality issues lately, including deansbimmer

It does seem like it is something restricting flow, either a bad/blocked rad, or a tstat not opening fully could cause this.

edit, he mentioned it here: https://www.m3post.com/forums/showth...8#post31780043

[Lienrocs]

Originally Posted by tdott

I know you mention brand new parts, but I just wanted to point out it's still possible you got a faulty part. Sucks, but possible. I know a few have complained about do88 quality issues lately, including deansbimmer

It does seem like it is something restricting flow, either a bad/blocked rad, or a tstat not opening fully could cause this.

edit, he mentioned it here: https://www.m3post.com/forums/showthread.php?p=31780043&highlight=do88#post31780 043

Faulty parts are possible for sure. I was already thinking about swapping the rad out for a different unit and see what happens. The new do88 rad doesn’t have a drain plug so all of this messing around is extra messy.

[omgzirra_exe]

i don't think poor heat extraction is the problem, but i do think COTA is the problem lol.

180F while cruising is 30F below standard operating temp.

but something somewhere isn't working... i just can't pin point it from your provided list of replaced parts.


Also what are you using to log the temps?

[kolosy]

Maybe a stupid question, but is your ambient temp sensor working? omgzirra_exe ‘s point about it being below standard at cruise makes me wonder if it’s running the fan at the wrong times?

[Lienrocs]

Originally Posted by omgzirra_exe

i don't think poor heat extraction is the problem, but i do think COTA is the problem lol.

180F while cruising is 30F below standard operating temp.

but something somewhere isn't working... i just can't pin point it from your provided list of replaced parts.


Also what are you using to log the temps?

All installed in the last several hundred miles and all brand new:

OE GT4 water pump.
OE thermostat.
Do88 radiator
Do88 PS cooler
Do88 dct cooler
Litchfield oil cooler
New ac condenser (also pulled it entirely and the car still overheated)
Epic oil thermostat delete (an lines and improved racing 185 degree full flow thermostat installed)

Zebulon splitter, no factory under tray but all radiator seals in front and behind the rad are in place and brand new.

Factory ambient sensor reading normal.

The fan kicks on after the thermostat is open. I don’t know exactly when it should come on but it doesn’t seem out of sync with common sense.

[amg6975]

Originally Posted by Lienrocs

Faulty parts are possible for sure. I was already thinking about swapping the rad out for a different unit and see what happens. The new do88 rad doesn’t have a drain plug so all of this messing around is extra messy.

That's odd, my DO88 rad does have a drain.

Something is definitely wrong with one of your new parts, my guess is your radiator is blocked/defective or the thermostat is defective and not opening all the way.

[former 240 s14]

What tool, gauge, etc are you using to review the coolant temp? Have you tried hitting the radiator with an infared thermometer to verify?

Also, have you thought about doing an engine flush? There could be an obstruction in the coolant galleries of the engine block? Only other idea is air in the system. With all the parts you've thrown at it I'm leaning to an obstruction or air pocket.

Goodluck and sorry to hear about your luck.

Rubin

[Lienrocs]

Originally Posted by amg6975

That's odd, my DO88 rad does have a drain.

Something is definitely wrong with one of your new parts, my guess is your radiator is blocked/defective or the thermostat is defective and not opening all the way.

My old do88 rad had a drain as well.

[Lienrocs]

Originally Posted by former 240 s14

What tool, gauge, etc are you using to review the coolant temp? Have you tried hitting the radiator with an infared thermometer to verify?

Also, have you thought about doing an engine flush? There could be an obstruction in the coolant galleries of the engine block? Only other idea is air in the system. With all the parts you've thrown at it I'm leaning to an obstruction or air pocket.

Goodluck and sorry to hear about your luck.

Rubin

I have an aim mxp hard wired into can.

I’m going to snag an eom rad and try and run some engine flush through it.

[omgzirra_exe]

Originally Posted by Lienrocs

I have an aim mxp hard wired into can.

I’m going to snag an eom rad and try and run some engine flush through it.

should use one of those pressurized systems!

i hope you figure it out, it's sort of worrying the chance of Do88 being faulty is higher than usual.. i normally never went the CSF route since i felt they didn't do much compared to Do88 but maybe i might start recommending them to others if this is a common issue with do88.

then again maybe do88 downfall was when they got put on FCP list of available items lol.

[jmeenach]

Originally Posted by omgzirra_exe

should use one of those pressurized systems!

i hope you figure it out, it's sort of worrying the chance of Do88 being faulty is higher than usual.. i normally never went the CSF route since i felt they didn't do much compared to Do88 but maybe i might start recommending them to others if this is a common issue with do88.

then again maybe do88 downfall was when they got put on FCP list of available items lol.

I've been looking to pull the trigger on do88 after seeing some hotter temps at Thermal last month. Don't tell me this!