Car getting hot while driving...

[saylor]

if you go run it at 205 on the highway, then get to a stop, does it come back down to 190? every time? that may be your new operating range.

if it is 190 at idle at a stoplight, that's not so bad. if it can do that this july, that will be super even.

but on a traditional setup, usually it gets cooler not hotter when you get moving... unless something is wrong as mentioned above blockage poor flow etc.

that's a good lookin setup, it should cool your whole neighborhood. I vote lets try to get it working before ripping it out

as I understand thermostats, it is supposed to be fully open at the rated temperature. someone correct that is that is wrong.

a lower # will be fully open quicker. which may or may not be what you want. the coolant needs to stay in the tank long enough to get rid of some heat.

 

[68Bigred]

Guys all great ideas and all are appreciated for sure. So I'm going to trial this....I'm actually going to take the turn on of the fans higher. I'm going to get a 195/200 switch. The fans have always proven they can keep the engine about 190 even in hot days. So maybe taking the fans to 200 will allow them to shut off at highway speeds and not act like a block. Worth a shot.

 

[rags]

want to know where your thermostat opens? put it in a pan of water. heat it on your stove. use your heat gun to measure the temp. check to see that it opens fully and straight at any temp. off the shelf thermostats are junk. if i have one that i know works, i won't change it no matter how old or what the job. good point about the accuracy about the temp gauge also. trust nothing new. SG

 

[CanCritter]

De ja vous.....did same.....went through 3-4 temp range switchs..180..197...202...

 

[68Bigred]

So just ran the car in the garage. Only 60 out today. Watching my temp guage it heats up tad over 180 then the needle drops a bit so I can see the thermostat opening then few minutes later creeps back up and the fans turn on and took it back a tad but the fans will not shut off. So just ordered a switch that will kick the fans on at 200 and shut them off at 195. Let's see if that allows more air flow at highway speeds. I'll report back. I don't think I have a overheating issue, I have a fan adjustment issue. Fingers crossed

 

[CanCritter]

on a side note have had Bad new thermostats from store....

 

[cantflip]

Cancel the order... starting the fans higher will only bring your temps higher. Did you ever stick your hand out the window at 60 or 70 MPH? If your fans dont push your hand that hard when behind them, you dont have enough airflow for them to be pullers. Pusher fans are a nice addition for sitting in traffic and wont have the shrouding or restriction of pullers at speed (great for A/C). Clutch type belt driven fans will let airflow overrun the fan at speed, but on non-A/C cars without a clutch... similar operating temps to your car IN HIGH AMBIENT TEMPS ONLY. If your running that hot now... you could have real issues come summer.

It has all been said here before...
Look hard in front of the radiator, any scrap of plastic or asphalt paper was used to direct airflow through the radiator at speed.
Make your own temporary pieces from cardboard just to experiment.
Even a tiny "chin" spoiler under the core support will help force airflow through the radiator.

Once operating temperatures exceed the thermostat rating, the control is lost from that device. For a couple bucks try a new one if you think it isnt opening enough. With an old thermostat available just cut out the center... it will still act as a flow restricter, which you need, but you wont question how far its open. This just for diagnostics, but a good use of that old "stat".

It sometimes happens that the impeller of a pump run without proper coolant rusts away or the housing gets damaged from a failed pump.... these could cause insufficient flow of coolant and may match your condition if they are only minor concerns... With out disassembly you could watch the flow through the radiator cap opening... but suck the coolant out as much as you can first so you dont make too much mess (down to the cores is fine). there should be violent flow at higher rpms with the stat open.

The worst case that I can think of is if your block had scale in the cooling passages and wasnt properly cleaned/boiled out. Mineral scale from hard water and rust scale can act like an insulator and cause problems with cooling abilities and is not fun to clean out... try a radiator shop, the chemicals for this kind of flush are very harsh and not sold in parts stores... plus you have nasty chemicals to dispose of afterwards.

Also noticed your serpentine drive... it could be spinning the pump too slow for high speed driving. Dont fall in love with your upgrade parts until the issues are resolved. Testing a poorly working stock setup is tough enough. Next time make sure it works good and do the mods one at a time so you can make sure you havent induced the problem.

 

[68Bigred]

Well yall are right! My dam near 800.00 radiator is ***fed! Coolant looked nice and green but drained it down and this HTML class. Value is So home now going to it full of ****! They mush have not dipped this block when they rebuilt it. Some good news rigged up my pressure washer and lowered pressure down and I think got the crap out of it. Who knows what's still inside the motor. I'm going to put back together and try it....

 

[livininharrow]

you may be panicking too soon. most engines need to run at at least 210 degrees . too low a temp is actually damaging your engine more. you need the hot oil to lubricate properly and get rid of moisture. if anyone tells you differently than they have no idea what they are talking about. run a 195 stat and be happy. if you are sitting at a light and it goes up to 215 or so don't panic. the rad cap will do its job and keep you from boiling over.

 

[68Bigred]

Ok "cool" well after I got all the crap out driver for about 20 minutes. Never over probably 185. I didn't get on the hwy yet to see if it is better. Running straight water because I want to flush it again then will fill with coolant. Picture is idling after 20-25 minutes driving.

 

[CanCritter]

on my dodge ram went through 2 water pumps early...belive it was casting sand from the block..anyway just ramblein

 

[cantflip]

on my dodge ram went through 2 water pumps early...belive it was casting sand from the block..anyway just ramblein

They actually had a service message about that back in the 90s... Mexican block plant wasn't cleaning out the blocks good enough... I recall the message existed but never dealt with the issue... so I am a little fuzzy on the details.

 

[CanCritter]

They actually had a service message about that back in the 90s... Mexican block plant wasn't cleaning out the blocks good enough... I recall the message existed but never dealt with the issue... so I am a little fuzzy on the details.

was more or less just thinking about that and saw the dirty coolant and wondered how something similar would affect a mopar BB water pump..bottom line is a fella wants to keep coolant clean if he can..

 

[68Bigred]

Hopefully I can put this one to rest. Flushed it 4 times. Just filled up with coolant and took it about 20 miles at 75mph and didn't seem to get more than 185 190. But is oly 60 degrees out. I still think the fans need to cycle. They come on at 180 same time Stat opens. I still think going to put a higher switch in it. Ordered real nice lcd guage so I can see the temp better, enough for tonight..

 

[cantflip]

Hopefully I can put this one to rest. Flushed it 4 times. Just filled up with coolant and took it about 20 miles at 75mph and didn't seem to get more than 185 190. But is oly 60 degrees out. I still think the fans need to cycle. They come on at 180 same time Stat opens. I still think going to put a higher switch in it. Ordered real nice lcd guage so I can see the temp better, enough for tonight..

If you are seeing that much improvement, try the radiator shop for a thorough flush with a prolevel chemical agent... and always use distilled water. Believe it or not the cycling pure water will reabsorb some of the scale and help it continue to come free... more headaches, but also better cooling in the heads were you need it and really cant flush it, especially once assembled. I would imagine you will have several more flushes with a few months use in between before you see the last of this.

 

[66Newyorker]

When you put coolant back in. You only need enough to lube the system and pervent corrosion. If the lowest temp in Austin is around 32 degs. You only need about a gal or so for your system, not a 50/50 mix. After that put a bottle or 2 of wetter water. I have also found that my cars runs hotter highway speeds, around 205 or so. I think it may be air damming. Not being able to flow enough air through the engine compartment at higher speeds. Just my 2 cents.

 

[Knebel]

When I put an electric fan on my car and made my DIY shroud, I had the same issue. I have only one 16" Fan with an adjustable thermostat. It would be great in idle and traffic and at highway speed it would get crazy hot. The issue was the airflow, the shroud with inly the 16" hole was too much restriction. I ordered 5 or 6 of those "flaps" you have there and cut a bunch of holes in the shroud and covered them with the flaps. Have the same performance at idle and at highway speed the temp goes down so much, that I dont even need the fan. Standard radiator and 160° thermostat,, but want to upgrade to aluminium this summer because the overall temp was waaay hot at 115° ambient temp. And the fan was always on...

 

[68Bigred]

One thing also adding to this issues is last week I put 3.23 gears in it and now turning more rpm on the highway. Maybe I've had this issue but now with the gears it presented its self. I'm going to run it for awhile and then do what is suggested. Take it to a shop that can do a good chemical flush on it. I just have to keep an eye on it. Just hate the feeling of having to worry while on the road. I never drive the car far and I don't depend on it but in 3 years i have 2k miles on the car, this is supposed to be the year I enjoy it more. Heck last year alone I put 2k on my 85 renault alliance she always runs cool on about a gallon of coolant lol, but then again she is a 1.7l with 77hp, not 7.2l with probably 400hp.

 

[cantflip]

One thing also adding to this issues is last week I put 3.23 gears in it and now turning more rpm on the highway. Maybe I've had this issue but now with the gears it presented its self. I'm going to run it for awhile and then do what is suggested. Take it to a shop that can do a good chemical flush on it. I just have to keep an eye on it. Just hate the feeling of having to worry while on the road. I never drive the car far and I don't depend on it but in 3 years i have 2k miles on the car, this is supposed to be the year I enjoy it more. Heck last year alone I put 2k on my 85 renault alliance she always runs cool on about a gallon of coolant lol, but then again she is a 1.7l with 77hp, not 7.2l with probably 400hp.

Wow a Renault Alliance! I heard that Chrysler had put a bounty on those when they took over just so the salvage yards would crush them out of existence. I saw one mid 90s and thought it was odd then that they had all disappeared so fast... asked a local tow operator and was told they got spiffed when they brought one in.

 

[68Bigred]

Yep! Chrysler didn't want them to compete against the k car. They were not bad cars if they were maintained. Alot of misinformation about them. My first one had over 200k on it but rotted away when I was a kid. 40 mpg. This one just turned 53k. All original. Excuse my messy garage. One real bad thing is the 3speed auto, very clunky. Hunting down a 5 speed and will convert it. Slowly gathering parts