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View Full Version : Engine RPM/load and heat/overheat



MK2Racer
02-23-2005, 04:38 PM
Here's a strange one-
I was on the way to work, driving along in 5th. I noted that my temp guage was climbing. I remember in my white car the guage was broke, so if I tapped it it would go away, this was not the case here. After a bit, it kept climbing, but I noticed no change in my heat in the car. Generally, when I go into an overheating situation, I will lose heat in the car. Thought this was odd. I revved the engine to about 5k in neutral real quick and when I did, the temp dropped back to norm right away. It didnt creep again, however I thought I smelled antifreeze. I checked when I got to work, no leaks anywhere, nowhere wet. The core hoses, upper and lower rad. hoses, radiator itself, under the core on the floor, nothing. Maybe it was just my imagination, or it squirted out of the overflow tank or something??? On the way home, I was paying attention to my heat, and when the RPMS went up fast, or especially if I was under load (5th at low speeds and stand on the gas) the heat will get cold quickly. After a few seconds at normal RPMs (or no load) the heat returns.

Is this perhaps related to my overheating this morning? What would cause that, just air in the system? I jacked up the front and 'burped' it, and I couldnt get any more air out. I'm not low on coolant. I have a new radiator. I have a new water pump. Only thing I can think of is that under load I have not enough vacuum to keep the valve open and consequently the hot coolant does not reach the core, but wouldn't that do it on all cars then? Also, the core shoudl be hot enough that if I dont have circulating coolant for a few seconds I shouldnt get ice cold air, at least that's what I think. WTF, I'm kind of at a loss.

I'm going out there to look around now (I got off early) and will report any findings, but some suggestions are quite welcome, as I dont think I'm going to see anything I didnt see this morning.

TIA,
Ken

onephatcrackaII
02-23-2005, 05:13 PM
check your weep hole on your water pump... it might be leaking slowly about read to go. as far as the over heating more then likely its an air pocket from a slow leak somewhere... ie water pump. make sure no pin holes are in the radiator too... check both sides!.

StanS
02-23-2005, 05:30 PM
fan (liquid thermostat is going). Take a 1/8-1/16" wood slat and gradually apply it to the fan from passenger side of car at about a 20 deg angle at idle. If u can easily stop the fan, you need a new one. This could be an excuse to get an electric fan.

MK2Racer
02-23-2005, 06:46 PM
Its possible to be the fan, I'll check that out.

I have a brand new radiator and a brand new water pump, and I didnt see any coolant leaking. I parked the car in a clean parking spot and I saw a sheen of some sort of fluid when I left work; it looked more like gas, it had that rainbow effect as it was sitting on water, so I don't think it was antifreeze. Some other unrelated issue maybe, but I'll deal with that next, one at a time.


I was out there just now, I checked everywhere and I saw no leaking coolant, so it must have just been my imagination or maybe it did just squirt out the overflow tank. I checked the level and it was dead-on, so who knows?? I'm going to take it on a test run a little later on, so I'll report the results, but that is pretty confusing about the heat going away. It does that _every_ time I punch it, the temp needle only creeped once or twice and I only thought I smelled that antifreeze once.

I think I should note that my heat is NOT hooked up like normal. Since I swapped the 6m those VTV or VSV or DVV or whatever-the-hell you callem's under the washer reservoir would not work so I used a vacuum T and ran a line from the manifold over to the water valve to keep it open at all times.

85 rat rod
02-24-2005, 04:54 AM
I have a honda accord with a BHG and when the heat dissapears is usually a sign for me to pull over and add water to the system as this usually means that the system is dangerously low, not trying to scare you, just letting you know, my experience with miraculus heat misplacement.

82MKIILtype
02-24-2005, 09:36 AM
Pressure test the entire sytem. It's the only way to rule out a leak. Any leaks I've ever looked for I only found after it was too late.

Keyfoo
02-24-2005, 11:41 AM
If your overheating underload like up hills, ckeck your compression

last year mine was way to high and car temp would climb on hills
and go down fast on the flats. Had carbon buildup due to weak coil.
yet proformance was still good.