my 1998 D1 began to overheat significantly this weekend while on a family camping trip when I switched the AC on. The rover was running a little warmer than normal due to a moderate roof load but once the AC came on it wanted to peg out the gauge. I switched off the AC and it ran fine after that. Was the motor that strained from the roof load and AC it overheated or is there a better explanation?
Over heats w/ AC on
- Thread starter Ncrovr725
- Start date
Check to see if your condensor fans are running. If they are - my bet is your radiator has a partial clog and extra strain of the AC is just enough to overheat it.
I may be wrong, but here's my $0.02: a normally-running D1 is ridiculously difficult to overheat. It can be running with the ton of stuff on the roof rack, at 75 mph up a 6% grade at 110F outside, with A/C on full blast - and yet stay under ~230F. At this temperature, the stock D1 temp gauge stays rock solid in the middle - pretty much the same as 180F. If you see the needle creeping higher, whatever are the conditions, chances are pretty high that things are not all right.
One thing you might want to take a look at is your fuel rail pressure. Get to harbor freight and get a fuel pressure gauge and check it. It's a tool you should have anyway, they are pretty cheap and really easy to use. You should be closer to 35psi if it's in good shape.
My fuel pump is going out but the truck has been running on less than 18psi for months now. The bad, hot starts and stalling at idle have been happening to me too. With the A/C on it makes it much worse.
My guess is that the engine in running really lean due to lack of fuel. The lean condition causes the engine to run hotter than normal and with the A/C on the engine runs really hot. Throw in all the camping gear and people and I bet mine would do the same thing.
Just a guess though...
My fuel pump is going out but the truck has been running on less than 18psi for months now. The bad, hot starts and stalling at idle have been happening to me too. With the A/C on it makes it much worse.
My guess is that the engine in running really lean due to lack of fuel. The lean condition causes the engine to run hotter than normal and with the A/C on the engine runs really hot. Throw in all the camping gear and people and I bet mine would do the same thing.
Just a guess though...
Last edited:
What year were electric fans added to DI? My '96 doesn't have electric and it is an SE7.
My '96 was overheating exactly as Ncrovr725 described. I replaced the fan clutch with the GM non-AC clutch and used an S10 fan. A few days ago we drove up a canyon here in AZ with AC on and a good passenger load, about 90F ambient. Engine management showed max temp at 217F and that was 10-15mph driving. It dropped quickly when we could go a bit faster for short periods.
My truck has 180K on it; I don't know that it has ever had a full radiator flush but that is my next step.
My '96 was overheating exactly as Ncrovr725 described. I replaced the fan clutch with the GM non-AC clutch and used an S10 fan. A few days ago we drove up a canyon here in AZ with AC on and a good passenger load, about 90F ambient. Engine management showed max temp at 217F and that was 10-15mph driving. It dropped quickly when we could go a bit faster for short periods.
My truck has 180K on it; I don't know that it has ever had a full radiator flush but that is my next step.
Injuhneer said:
The electric fan set up is in addition to the main engine cooling fan (the big one with the fan clutch). If you have A/C you will have this setup.
The electric assembly is located in front of the A/C condenser, behind the grill. The main fan does the work of cooling the engine by pulling air through the radiator, the AUX fan only pushes air through the condenser.
If his fan cluch is slipping when it should be at full lock up I can see where that would cause his truck to do this with the extra heat from the condenser and the extra load.
Last edited:
Mine was overheating - thermostat was OK, electric a/c fans worked, radiator OK, no blown head-gaskets, etc. Fan clutch was replaced with a HD one from NAPA has been fine since.
You should have your radiator flow checked and rodded if necessary, but it could just have a bunch of crud blocking airflow through your radiator. I had the same problem (although I never let it get much passed normal on the gauge) which ended up being an excessive amount of pine needles and cat hair in the coil fins which I couldn't really see until I was rinsing it out. My flow was fine when I had it out to clean but I change my coolant every 2 years.
Last edited:
this has been discussed many times... use the search function. lots of good info re this
check fan clutch (located on engine fan) check condenser fans. you can look through your front grill and see them (there are 2) on a d1 they go on everytime you run the ac... if they are not working that could be your culprit
check fan clutch (located on engine fan) check condenser fans. you can look through your front grill and see them (there are 2) on a d1 they go on everytime you run the ac... if they are not working that could be your culprit
Last edited:
jmonsrvr said:
Yup and now that it's getting warmer out it is going to be discussed at least 5 times a week. Roasted fan clutchs and radiators clogged due to never being flushed all day... Hope you're ready
jmonsrvr said:
Do you realize that in most cases "the search function" primarily brings up posts with the question the post is asking about being answered with "use the search function". Alternately and on other forums it ends with "PM me your number and I'll walk you through it."
OK, so knew that my truck has no electric fans. I just went to check to be certain; no fans. The mounting points and power connectors are there but no fans. Looks like someone removed them.Busted_D1 said:
Ah, the joys of (some) previous owners.
Last edited:
Its just like an engineer to not notice missing electric fans and jump into mechanical fan upgrades with both feet.
my 95 lwb overheats when sitting in traffic with the ac on any day the temp gets above 80. happens to be a big pain in the ass when you have a 2 year old in the back and you're forced to roll down the windows. i planned ahead this year and already have a radiator and heater valve ready to put in this weekend (the valve has been weeping). unless you're cruising down the highway, on hot days these things really need a clean radiator and both fan setups working.