Hot after highway cruise?
11-08-2010, 09:05 AM
#1
Hot after highway cruise? This may be a silly question, and I've searched all around here and the web trying to find a solid answer.
After taking the car on a 20 minute + drive on the highway (temp steady at 175*, 70* ambient) and then exit to a stoplight and the trans temp gauge shoots up 20-25 degrees in a matter of about 2 minutes. After it gets moving again it cools off pretty quick, back down to around 175-180* in a matter of 5 minutes or so of steady cruising. Generally what could cause this?
Setup is:
Manual Valvebody 4L80
Stock cast aluminum short pan
Fuddle 3200 converter with Lockup
B&M 11"x11" cooler
Trans temp sender in pan
After taking the car on a 20 minute + drive on the highway (temp steady at 175*, 70* ambient) and then exit to a stoplight and the trans temp gauge shoots up 20-25 degrees in a matter of about 2 minutes. After it gets moving again it cools off pretty quick, back down to around 175-180* in a matter of 5 minutes or so of steady cruising. Generally what could cause this?
Setup is:
Manual Valvebody 4L80
Stock cast aluminum short pan
Fuddle 3200 converter with Lockup
B&M 11"x11" cooler
Trans temp sender in pan
Last edited by Photochop; 11-08-2010 at 09:23 AM.
11-08-2010, 01:30 PM
#2
There's probably more air flowing through your 11x11 trans cooler while the vehicle is moving, which makes your cooler do a better job of cooling the trans fluid. I'd imagine that while you're at cruising speed, your converter is locked up, which is also keeping your trans temp down.
Is your cooler mounted in a way that the factory fans will pull air through it?
Also, are you using the stock trans cooler in the radiator?
Is your cooler mounted in a way that the factory fans will pull air through it?
Also, are you using the stock trans cooler in the radiator?
11-08-2010, 01:40 PM
#3
Well I thought the same thing, but I can putt it around town in stop and go and its pretty consistent around 160-180. It spikes like this the most after a highway cruise...just found it a little odd. Its a factory M6 car, so no cooler in the radiator, engine temps around 180-190 (180 thermostat).
When I first got the 11x11, I mounted it in front of the radiator, but it was doing this same thing. So then I moved it down lower, dope style, and its still doing the same thing when I pull off the highway. My guess now is an issue with how the FMIC is mounted vertically and insufficient airflow at a stop like you mentioned.
Due to how the FMIC is mounted and not wanting to mess with it, my only other good idea was to mount a fan in front of the cooler and have it controlled via thermostat based on trans fluid temp. I just wanted to eliminate any other fixes or come up with other ideas before spending money on the fan in front of it. I thought maybe the stock aluminum pan would hold in more heat and not dissipate as well as a deep pan would, but don't really know how much this would help the situation either.
When I first got the 11x11, I mounted it in front of the radiator, but it was doing this same thing. So then I moved it down lower, dope style, and its still doing the same thing when I pull off the highway. My guess now is an issue with how the FMIC is mounted vertically and insufficient airflow at a stop like you mentioned.
Due to how the FMIC is mounted and not wanting to mess with it, my only other good idea was to mount a fan in front of the cooler and have it controlled via thermostat based on trans fluid temp. I just wanted to eliminate any other fixes or come up with other ideas before spending money on the fan in front of it. I thought maybe the stock aluminum pan would hold in more heat and not dissipate as well as a deep pan would, but don't really know how much this would help the situation either.
11-08-2010, 05:40 PM
#4
That's a tough one. Is there any chance your trans cooler could be partially clogged? It's pretty easy to tell if you can run the car for a little while, and then park it and feel the cooler for cool spots.
I know some of those B&M coolers have built in cold-weather bypass thermostats - does yours?
Are any of your cooler lines close to or touching any exhaust or other hot parts? Maybe they heat up while you're running it on the highway, and then when you slow down there is no airflow around the parts, and heat from the exhaust radiates onto the trans cooler lines, etc.
I know some of those B&M coolers have built in cold-weather bypass thermostats - does yours?
Are any of your cooler lines close to or touching any exhaust or other hot parts? Maybe they heat up while you're running it on the highway, and then when you slow down there is no airflow around the parts, and heat from the exhaust radiates onto the trans cooler lines, etc.
11-08-2010, 07:17 PM
#5
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Fan settings are sucktastically high on these cars, you
were getting rolling airflow and running at the thermostat
pivot temp, and then you had none and waited for the
fans to kick. When fan-limited you are not thermostat
controlled, you're PCM-controlled.
were getting rolling airflow and running at the thermostat
pivot temp, and then you had none and waited for the
fans to kick. When fan-limited you are not thermostat
controlled, you're PCM-controlled.
11-08-2010, 09:02 PM
#6
That's a tough one. Is there any chance your trans cooler could be partially clogged? It's pretty easy to tell if you can run the car for a little while, and then park it and feel the cooler for cool spots.
I know some of those B&M coolers have built in cold-weather bypass thermostats - does yours?
Are any of your cooler lines close to or touching any exhaust or other hot parts? Maybe they heat up while you're running it on the highway, and then when you slow down there is no airflow around the parts, and heat from the exhaust radiates onto the trans cooler lines, etc.
I know some of those B&M coolers have built in cold-weather bypass thermostats - does yours?
Are any of your cooler lines close to or touching any exhaust or other hot parts? Maybe they heat up while you're running it on the highway, and then when you slow down there is no airflow around the parts, and heat from the exhaust radiates onto the trans cooler lines, etc.
Cooler has no thermostat, its just a 11x11 super cooler with a couple of 1/2 npt ports that I put 6an adapter fittings in.
External heat was a concern. Since I wrapped the turbo crossover that runs around the rear of the trans with heat wrap, still hot. I've got some heat wrap tape I'll wrap the lines in. They're not right next to anything hot, but the exhaust is in the area.
Yeah, I thought about that too. I think I'll relocate the cooler up in front of the radiator, and get a small pusher fan thats thermostat controlled with the fluid temp and see what happens.
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11-09-2010, 10:16 AM
#8
Honestly I think it would be cheaper to run a fan right on top of the cooler. Swapping radiators would be a lot more hassle and cost more due to having to build new braided 6AN lines to/from it, and I have mixed emotions about running the cooler in the radiator
11-09-2010, 04:48 PM
#11
Low vacuum = high line pressure. Whats your vacuum at idle?
11-09-2010, 06:15 PM
#13
Are you cruising with the converter locked? Mine generally cruises at about 40* over ambient on the highway, but shoots up to 160-180 when cruising around town (might hit 200 once a summer in town) but mine is rollerized, so I'm sure that helps some with heat. I probably have the same 11x11 (29,200 BTU) cooler mounted dope style.
11-09-2010, 07:51 PM
#14
Are you cruising with the converter locked? Mine generally cruises at about 40* over ambient on the highway, but shoots up to 160-180 when cruising around town (might hit 200 once a summer in town) but mine is rollerized, so I'm sure that helps some with heat. I probably have the same 11x11 (29,200 BTU) cooler mounted dope style.
Yep, any time it's cruising at a steady speed in 3rd or 4th I lock it up. I think I've narrowed it down to what's probably goin on. First off the converter is used, got it from cablebandit on here. He mentioned that he ran the converter locked at the track a couple runs and its possible that it slightly burnt the lockup clutch as the paint is slightly bubbled on the case of the converter in one spot. It still holds lockup for cruising but I never lock it under any kind of heavy throttle.
2nd is the engine/turbo delivers alot more heat than the average f-car. This may be heating up the cooler lines. I'm going to wrap them in heat resistant tape soon and see if that helps.
Lastly is with the turbo setup the front end air flow path is less than ideal due to the FMIC sitting upright. I'm going to remount the cooler in front of the ac condenser this weekend and have my tuner set the fans to come on around 160-170* or so to see if all this helps.
Thanks for the suggestions guys, any other ideas are appreciated
11-10-2010, 11:00 AM
#15
One more thing I thought of, which may or may not have something to do with it. I'd experienced what I think is converter drainback a couple months ago with this thing, and I think its gotten worse lately. It felt like it did it this morning when I hopped in it to drive in to work, and did the same thing on saturday when I took it for a drive. If this drainback is getting worse, could this be what its doing when I exit the highway and come to a stop? Fluid draining back into the pain from the hot converter causing the fluid temps in the pan to rise?
Last edited by Photochop; 11-10-2010 at 11:10 AM.
11-10-2010, 11:51 AM
#16
That 15 - 16 I hope is vacuum, not line pressure.
Does this trans have a transgo kit that eliminates runaway line pressure?
My 4L80E gets hot at low speed to a stop because of a worn boost valve and higher than normal line pressure. I just replaced the boost valve with a Sonnax 30,000 miles ago and it's worn again. The boost valve wears and leaks pressure into the torque signal circuit which signals the boost valve to up the pressure. I've been told it's not uncommon to replace the boost valve this often.
As for the converter draining back, it wouldn't when it's running. It would be a crossleak when running because it's all under line pressure. Crossleaks can cause various problems.
Does this trans have a transgo kit that eliminates runaway line pressure?
My 4L80E gets hot at low speed to a stop because of a worn boost valve and higher than normal line pressure. I just replaced the boost valve with a Sonnax 30,000 miles ago and it's worn again. The boost valve wears and leaks pressure into the torque signal circuit which signals the boost valve to up the pressure. I've been told it's not uncommon to replace the boost valve this often.
As for the converter draining back, it wouldn't when it's running. It would be a crossleak when running because it's all under line pressure. Crossleaks can cause various problems.
11-11-2010, 09:29 AM
#17
Haha, 15-16 was vacuum figures
Thats interesting about the boost valve, what all is involved in changing those out? I may be going to a deep pan in the off season, I'd likely change that valve out then.
I did a web search about drainback and 4l80e's, I guess it's fairly common. I'll just let it idle a bit longer before leaving if I haven't driven it In a few days from now on.
Thats interesting about the boost valve, what all is involved in changing those out? I may be going to a deep pan in the off season, I'd likely change that valve out then.
I did a web search about drainback and 4l80e's, I guess it's fairly common. I'll just let it idle a bit longer before leaving if I haven't driven it In a few days from now on.
11-11-2010, 10:01 AM
#18
The boost valve can be accessed with the pan off. Just need some inside snap ring pliers to get it out.
TransGo does have an extra wide boost valve thats supposed to eliminate this problem. I don't know whats been done to your trans but I wouldn't take their valve out and put an other brand in.
First though you should check the pressure, it might not even be the problem, I'm just throwing that idea out there because I know it's my problem.
TransGo does have an extra wide boost valve thats supposed to eliminate this problem. I don't know whats been done to your trans but I wouldn't take their valve out and put an other brand in.
First though you should check the pressure, it might not even be the problem, I'm just throwing that idea out there because I know it's my problem.
11-11-2010, 10:16 AM
#19
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I know its apples to oranges, but I really like my derale tranny pan on my 700r4. with the cooling fins and extra capacity, it will help. probably be cheaper than any other reasonable alternative.
4l80e link
4l80e link
11-11-2010, 08:10 PM
#20
Does that trans pan hang below the oil pan?
I know its apples to oranges, but I really like my derale tranny pan on my 700r4. with the cooling fins and extra capacity, it will help. probably be cheaper than any other reasonable alternative.
4l80e link
4l80e link
