View Full Version : Engine High temperature, highway use.
madstudios
04-16-2017, 04:16 PM
Hi everyone!
Last weekend for some reason (air on the system or bad otterstat), my fans did not came on, and my car overheated (220 mark) I turned off the engine as soon as I saw the temperature increasing.
I've replaced the otterstat and now the fans are working properly again.
But I've always noticed that my car's temperature runs colder in the city, even with intense traffic, and hotter in the highway. Is this normal?
This is today's max temperature after 90mile trip.
https://uploads.tapatalk-cdn.com/20170416/ef6a28959da4e3421d76700a235cac7d.jpg
I usually use AC all the time.
I think I have the automatic air bleeder installed, is that right?
And I've recently replaced my old fans with new ones from Delorean Parts Northwest (wings b cool fans), but the temperature looks the same to me, compared with old fans.
https://uploads.tapatalk-cdn.com/20170416/f500a4a176c0d48da03820207c8eb256.jpg
Thanks!
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Bitsyncmaster
04-16-2017, 04:41 PM
Unusual for it run hotter at highway speeds since you should be getting more air flow through the radiator. It could be your working the engine harder at highway speeds.
With your AC running the fans run when the AC compressor is on so maybe your overheat was not caused by the otterstat. Make sure your fans do turn on when you switch the AC on.
If you have an OEM radiator, I would consider one of the vendors replacements. You may also consider a flush if you have not done that already.
madstudios
04-16-2017, 05:42 PM
Unusual for it run hotter at highway speeds since you should be getting more air flow through the radiator. It could be your working the engine harder at highway speeds.
With your AC running the fans run when the AC compressor is on so maybe your overheat was not caused by the otterstat. Make sure your fans do turn on when you switch the AC on.
If you have an OEM radiator, I would consider one of the vendors replacements. You may also consider a flush if you have not done that already.
Yes, my fans turn on with de AC on.
My radiator looks like have never been replaced, I'm considering replacing it, but I'm going to flush the system before that.
I also noticed a really small leak in the radiator (drivers side).
https://uploads.tapatalk-cdn.com/20170416/67be9c9341b8c80f35ef822ff2308829.jpg
https://uploads.tapatalk-cdn.com/20170416/3562dfeea21fde650f76493653c71da2.jpghttps://uploads.tapatalk-cdn.com/20170416/780934580fb4f1358314c2bcdbde8da7.jpg
Thanks!
Fernando Silotto. Sao Paulo - Brazil
Delorean Vin 3772
Brian_SS_TT
04-16-2017, 08:07 PM
I wouldn’t be surprised if your front license plate had a negative effect on airflow thru the radiator at highway speeds...could be forcing air around the plate and along the side of the scoop/spoiler.
sdg3205
04-17-2017, 01:56 AM
Yes, that license plate is in a bad spot.
During a rally a couple years ago i had an event plate zip tied to my intake grill. The car ran noticeably hotter and the fans were on almost constantly.
Chris_Von_Bron
04-17-2017, 02:17 AM
I had the same thing and it was down to my coolant level having dropped enough to cause fluctuating temperatures. It looks like me you have breather fitted to the coolant tank so that should eliminate any airlocks. In my case I had a jubilee hose clamp not quite tight enough causing the drips of coolant to be lost over a period of time. In your case this could be down to your leaking radiator or hose clip to it?
Try topping your coolant up and see on a highway test run if the issue goes away?
DaraSue
04-17-2017, 02:29 AM
Have you had any issues with rust/sediment in your cooling system? I had a similar problem when I first got mine, most of the time it would be fine, sometimes it would randomly start creeping up past the 220 mark. It only ever happened once or twice on surface roads, every other time was at freeway speeds. That particular issue abated after I had the thermostat it came with replaced (it was rust-colored and probably all jammed up with crud) but I had a bunch of other leakage issues after that, had practically the entire coolant system replaced and then finally gave up and had the heads pulled and all the rust cleaned out, because the block was rotted all to crap due to the PO having apparently left it sitting with water in the lines since 1993 or so. :shameful: It runs good now, though! (At least temperature-wise...)
madstudios
04-17-2017, 09:33 AM
I wouldn’t be surprised if your front license plate had a negative effect on airflow thru the radiator at highway speeds...could be forcing air around the plate and along the side of the scoop/spoiler.
Good observation, it makes perfect sense!
I'll move the license plate to the bumper, and test for next weekend!
Thank you
Fernando Silotto. Sao Paulo - Brazil
Delorean Vin 3772
dn010
04-17-2017, 09:34 AM
Your radiator looks wet at the joint where the plastic tank is crimped to the actual radiator core. That to me would indicate the tank is separating away; even if it isn't, it's only a matter of time before it does - I'd replace that radiator ASAP.
madstudios
04-17-2017, 09:35 AM
Have you had any issues with rust/sediment in your cooling system? I had a similar problem when I first got mine, most of the time it would be fine, sometimes it would randomly start creeping up past the 220 mark. It only ever happened once or twice on surface roads, every other time was at freeway speeds. That particular issue abated after I had the thermostat it came with replaced (it was rust-colored and probably all jammed up with crud) but I had a bunch of other leakage issues after that, had practically the entire coolant system replaced and then finally gave up and had the heads pulled and all the rust cleaned out, because the block was rotted all to crap due to the PO having apparently left it sitting with water in the lines since 1993 or so. :shameful: It runs good now, though! (At least temperature-wise...)
I'll have that check too, it's a possibility!
Thank you!
Fernando Silotto. Sao Paulo - Brazil
Delorean Vin 3772
madstudios
04-17-2017, 05:03 PM
Your radiator looks wet at the joint where the plastic tank is crimped to the actual radiator core. That to me would indicate the tank is separating away; even if it isn't, it's only a matter of time before it does - I'd replace that radiator ASAP.
Yes, it's a matter of time...It has a really small leak, but replacing the radiator it's my next priority.
Fernando Silotto. Sao Paulo - Brazil
Delorean Vin 3772
David T
04-17-2017, 07:47 PM
I wouldn’t be surprised if your front license plate had a negative effect on airflow thru the radiator at highway speeds...could be forcing air around the plate and along the side of the scoop/spoiler.
GOOD PICK-UP! I missed it but you spotted it. That plate mounted where it is, blocking the inlet, will definitely cause problems at highway speeds. As for the rad, if it is the original and it is leaking, your choice is clear, it must be replaced and sooner rather than later.
madstudios
05-15-2017, 02:57 PM
I've removed the radiator, was really dirty inside! New radiator installed, problem solved!
solved!
Fernando Silotto. Sao Paulo - Brazil
Delorean Vin 3772
Good observation, it makes perfect sense!
I'll move the license plate to the bumper, and test for next weekend!
For future reference.
If your below-bumper mount is attached to the rock screen bolts try moving it 1 or 2 bolts to the left or right, off center, before going up to the bumper.
The air can go around it fine when the fans run no matter where it is. Small difference, if any, due to center-low location once the fans come on. And no difference at all when car is stopped or moving slowly.
Glad the new radiator got you back in shape.
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