95 Lumina APV 3800 Overheating Issues

Hello all, every since summer started I've noticed my engine temperature increasing for obvious reasons. But the temperature significantly increases when my car is idling i.e in heavy traffic or just normal idling. But as long as the car is moving and air is passing through the temperature is pretty much stable (about halfway).

I had this issue from before which has been resolved
http://www.automotiveforums.com/vbulletin/t438685.html

I have replaced the thermostat, repaired the water pump. The only thing now I can think of is that the radiator is not doing its job, because it is clogged or malfunctioned. The fan works and the only way I can reduce the engine temp is to crank the heating to full. So for example if it is say 30 degrees outside, in my cabin it would be about 36 degrees or more haha. I talked to another person about this, and they say to flush out the radiator.

Is it hard to remove the radiator?

Any help would be great!!

Thanks !!!

"Flushing" a radiator rarely solves such problem. MOst often very thin mineral deposits from hard make-up water impair heat transfer and this does not go with a "flush".
Make sure there is no external clogging at A/C radiator from vegetation . Also, make sure fans work specially if A/C is used at idle. I kind of understand the problem alleviates or disappears when running at highway speeds and this rules out engine problems.....

TO remove radiator requires detaching the dogbone at radiator and swing rearward. then, as the book says:
- remove forward lamp harness from fan frame and unplug fan connecetor
- remove fan attaching bolts
- remove fan and frame assembly
- remove hoodlatch (mark position to ease reinstallation)
- remove coolant hoses, transaxle coolant lines and radiator support bolts
- remove radiator.

Thanks for the reply LMP. Also I forgot to mention that since I fixed my PCM ~2 years ago, my check engine light still comes on. I've noticed it comes on right when the temperature gauge reads just below 1/4 (assuming Cold = 0 and RED hot = 1).. There seems to be no issue with the engine, so it's been on since.

OK, after more reading, and observing I've noticed that the fan on the inside of the radiator (the larger one one on the driver side) is not spinning. I pulled out the connection and measured the voltage and it gave ~14 volts when the A/C was turned on. With the A/C turned off the voltage was ~0.00x volts.

Is there anyway to test the fan? or do I need to pull it out and put 12volts through it?

If you can reach the plug as is, use wires to suit , feed 12V on fan side of the plug to test the fan. This figures as a rational explanation to our problem.

Hey LMP, I tested the the fan with 12volts and it spins!?!?

so nothing is wrong with the fan. When the AC goes on it still produces voltage, yet the fan does not spin..

Is there a relay of some sort?

relays are here (next to right hand headlight cluster)
www.avigex.ca/xport/relays.jpg
NOw if you cna measure 12V reaching the plug with A/C on but when the fan is disconnected, this might indicate a fouled/corroded plug or bad relay contacts.... easy to measure 12V at no load, but the voltage drops down as soon as a load is applied....

ugh... i checked the relays and they all seem to be working..

the fan relay is the only one with 5 pins...

LMP could u explain how to test for a
"this might indicate a fouled/corroded plug or bad relay contacts."

Thanks !!

Well sometimes connectors seem to make a connexion and do not because of corrosion or heat damage.
...this diagram www.avigex.ca/xport/fandiagram.jpg
shows only 4 relay contacts are active. ALso make sure you have checked for the right relay: the picture said the relays are not shown necessarily in proper sequence. IN fact, the only relay i diagrams that actually uses 5 contacts is the fuel pump relay.... www.avigex.ca/xport/fuelcontrol_iac.jpg

The relay can have a normally opened and a normally closed contact, but here only the normally opened is used...so you could swap relays for a test as relays that have only 4 contacts simply miss the normally closed contact that is not used here anyway.

If that does not change a thing, sInce you say the fan is OK and there seems to have 12v at the fan plug , I would disconnect the connector, then plug a pair of wire from the plug (feed side); activate A/C to check for voltage then if voltage is there, connect the wires to the fan side of the plug and the fan will either run or not...: if it runs, then it proves you have made a better contact and the plug is the culprit...

I was thinking that that fan relay had 5 pins, because I searched Rockauto.com and it says that

1995 CHEVROLET LUMINA APV 3.8L 231cid V6 MFI (L) : Electrical-Switch & Relay : Fan Relay ACDELCO Part # 158719 More Info {5 PIN, MINI, BLACK #12193601}
RELAY,FAN CONT CODE 3601

And regarding the a bad plug, I have disconnected the fan plug, and run my own wires to the fan, but the fan did not run. The voltage during this was lowered though to about 10v, and I just assumed it was due to a poor connection I have made with the wires.

I went to get the engine code read today, and it gave a code of DTC P1640.
They gave a print out of "possible errors" seems to be something with the Quad driver module (QDM).. Any ideas?

I found this link with google that has something to do with the fans and the DDM http://www.autozone.com/images/cds/gif/large/0900823d800f1b77.gif



Update

So I was driving around tonight noticed vibrations in the car, and was kinda worried about what was going on. Seems the fan started to run, I noticed my engine temperature at a very good level. Only thing I could think of today that I did different was jiggled and checked the relay wires, got the ODB code read, filled a bit of premium the other day, and filled regular today??? haha

hopefully the fan will keep running, and I fixed a faulty connection somewhere.

Now what is this Quad driver module error? the problems...


Side question, would premium gas be better then regular for this van? or would it show no significant difference?

Quad driver is an electronic power driver that runs the relays on and off. If for some reason one of the relays makes a weird contact, the voltage at the driver will read erroneous and you will have that code which does not indicate a failed driver, but an unusual voltage condition at the driver, the cause of which can be anything . SO....there was probably a poor contact somewhere that you have indeed corrected unknowingly...ehh...il will probably come again....
And yes, the 5 contacts relays are used all across the board, and only relevant contacts are used.
...and I would not throw my money out using premium gas. The advantage is there only if you have the compression ratio that requires it and the advantage comes from the compression ratio, not from the gas "energy contents" that is same as regular: it is just the fact that in a high compression ratio engine, regular gas would ignite prematuraly causing knocking and, with computer cars, would induce an extremely retarded spark that would then impair power....premium gas is just able to withstand high compression without exploding by itself: it will still wait for the spark.

Ok I have the same exact problem, When I bought my van it got hot when I sat at idle culprit...Fan not spinning. Fix: Relay for Fan After I replaced the relay the fan spun, but it didn't kick off while the van was running. Weird I had never heard of this proplem. The only way it would run was if I kept the defroster on but I can keep it on cool. Any ideas, and yes my CEL comes on EVERY time I start the van. Also my cluth on my A/C compresser wont engage and my A/C fan wont spin.

Have you changed the thermostat?

Also what was the problem from the CEL

...(continued)..
YOur "quad driver" code was relevant with your problem: it could tell that at the time the fan relay was ordered to run, the condition of the circuit was not normal...like an open contact to the fan relay coil. It seems you have fixed that by jiggling with the wire bundles or plugging/unplugging the relays. Was the code cleared at time of reading? If not, Disconnect the battery (disconnect main wire with a red cover near brake booster on firewall) and turn light switch to ON to drain any residual charge for say 10 minutes to clear the codes,(well this worked with OBD1..not sure with '95 OBD1/2 or 2) this to see if they come again, and report.

...(continued)..
YOur "quad driver" code was relevant with your problem: it could tell that at the time the fan relay was ordered to run, the condition of the circuit was not normal...like an open contact to the fan relay coil. It seems you have fixed that by jiggling with the wire bundles or plugging/unplugging the relays. Was the code cleared at time of reading? If not, Disconnect the battery (disconnect main wire with a red cover near brake booster on firewall) and turn light switch to ON to drain any residual charge for say 10 minutes to clear the codes,(well this worked with OBD1..not sure with '95 OBD1/2 or 2) this to see if they come again, and report.


Thats genius!! I knew they all tied in together some how. I'll try the restart and report back.

Since I hope your feeling generous with your knowledge, how would I repair/cure transmission slips? I seem to get them when I turn and try to accelerate hard(to a point). Also when I stop hard, I won't be able to move until the rpm's seem to drop.

I hope you say changing the transmission fluid lol..

Thanks again!!

I just tried to reset the engine light, but to no avail. The engine light was initially off at the start, but quickly came back on.

Maybe an error still? or need to reset it with the ODB II.

If an authentic OBD2, it can...may be it must... be cleared with the scanner. I'm not sure though this year model has a standard OBD2 plug...otherwise it needs an adaptor ..
NOw this problem you mention about kind of stalling when turning has been mentioned several times on this or the Transport forum and also the Bonneville forum..and I suspect on other GM forums all using same engine transmission combinaison. Most said it was when turning right. HOwever there was not (that I saw..may be in Buick or Oldsmobile forums I did not or seldom read) a clear and definitive solution brought forward....
However, as soon that happens to me, I would certainly drop the transmission pan and change the filter and fluid....it did solve same problem with my early Chrysler 300..at lteast for some time. A clogged filter can cause that behaviour...but it also indicates a lot of debris have come from worn out clutches....and I had eventually to replace all clutches....at the time, you could pull the transmission from under quite easily....I'd rather not be forced to do it on this model...but several did....
www.avigex.ca/xport/4T60photo.jpg

wow, pullin out the transmission seems like it would be tons of work.

I may just change the fluid and filter first, to see if that makes a difference.

Where is the filter located?

Just slip under car and the transmission oil pan is all there at hand without obstruction. You just need a very large funnel to channel all the transmission fluid to some container as it starts to escape all around as there is no drain plug. Then the filter is next.
THe filter kit I have comes without a gasket. Oil pan gasket can be genuine (as shon in manual) or rather liquid gasket might have been used..so get a tube of gasket goo.

So I got a chance to change the transmission fluid and filter, seems to have done the trick, no more slipping while I'm turning (mine occurred turning left).

I also put this Lucas Tranmission Fix into it too.
http://www.lucasoil.com/products/display_products.sd?iid=29&catid=2&loc=show

Shifting has gotten smoother, but I think it still slips if I brake hard and apply the gas.

OK Sorry about the delay I've been having tons of problems with this 3.8 and I'm about ready to shoot this darn thing with a shotgun. Ok now I cant get my CEL read, no one in my area can read the OBD1. Also mine is a 95 so I cant jumper it from A to B beause there is no connection for the B side. I have not found a way to fix my fan I have replaced the Fan relay and it made it work BUT it only works when I have the defrost on although latly it's been working when it wants to. As of right now I have 0 dollars so I cant do crap about it. And NOW I have a no start issue, I was hoping that one of ya'lls would find the culprit to this issue and I would be home free. It seems this problem happens everywere with about 95 percent of these vans yet chevy NEVER issued a recall?? This is very frustrating and if I blow a head that will be it I will be selling this van on here for the highest bidder. I only owe about 900 on it so if I can get twice that I'll deliver it as far as the mississippi and south as far as tennesse.

...I have replaced the Fan relay and it made it work BUT it only works when I have the defrost on ....
A/C is automatically set to ON with DEFROST . That is why the fans turn ON, just like with A/C. Most cars are wired like that as A/C acts as a dehumidifier and helps clear the fog from the windshield but I hate that and in my other car (Kia SPortage) I removed the physical switch from the internals of heater control. On the Transport however this is software controlled and you cannot change that.

Ah but my fan(s) DONT kick on, just my rad fan does. My ac fan has never worked and I dont get any voltage to the wires. Some one before me tapped into the hot side for the ac fan and had tried to run it to the rad fan, but it gets no voltage?? Still unsure why they did that I dont get any voltage were they tapped in either. I haven't found out why the ac fan and clutch on the ac compressor dosen't work either, I know something controls both of them but what I'm not sure as far as I know all my relays are fine. And yes my fuses are all good. I have replaced the thermostat and the coolant temp sensor (2wire), tommorrow I have to replace 3 wires on the starter solenoid they are completely worn through or green as cabbage from water corrosion. Is there anything else I'm missing its GOT to be electrical and I'm worried that the PCM has some issues. AND how do I manually clear the CEL I know you can but how. Thats it fer now some one write back soon please TY.