Hey everyone, been looking through the forums to see if anyone had an issue similar to mine but I feel like I have a little bit of everything going on...was hoping for some pointers as I try to get this fixed. Here are the facts:

- There's no muffler. Whenever there's a heavy rain, the car sputters, but this usually stops after a half mile or so. Yesterday, the sputtering didn't stop as I drove about 10 miles, on the highway, and the car started overheating pretty terribly by the time I got off the exit.

- Hood started smoking. Inspected, there was coolant everywhere and the reservoir was empty.

- Refilled coolant reservoir, started car back up - turned AC on, appears that one of the fans isn't working.

I'm going to work on the car this evening, any ideas as to why this might happen or what else I should be checking so I can spend the least amount of time/money on this thing?

 

- There is no muffler.
Install one. That doesn't have much to do with the other problems though.

-Whenever there is a heavy rain, the car sputters.
This is usually because the spark plug wires have bad insulation and the sparks short out when they are wet. Test that by misting water on the distributor and wires.

-Overheating.
Get the radiator completely full; start the engine cold with the radiator cap off. If coolant and air blow out of the radiator when you rev it up, the head gasket is bad. If that test seems OK, replace thermostat and try the fan bypass test below.

-Only one fan runs with A/C on.
That is normal. On model years 1992-2000, the condenser and radiator are independent from each other. Each one is half the width of the grille and has its own airflow and fan.

The radiator fan should run before overheating occurs. It's really only necessary when the car is stopped or moving slowly in traffic. You can bypass the fan thermal switch (on the thermostat housing, at the engine end of the LOWER radiator hose) and make the radiator fan stay on all the time the key is on. Test drive like that and if there's no overheating, replace the fan switch.

 

Sounds good, kemosabe. I'll let you know what happens.

 

Alright, I took the radiator cap off and gave it some gas in idle. No volcanic reaction, so I think we're good on the head gasket.

I unplugged the thermal switch (I'm assuming that's what you meant by "bypass"?) and it still overheated after my test drive (took about the same amount of time) - is there something else I should be doing to bypass it or is that what you meant, or should I replace the thermostat before I do the bypass test?

 

Unplug the switch and take a small piece of wire to jumper the two pins in the plug on the harness side. The fan should then start as soon as you turn the key on.

 

Okay guys and gals,
I have a 92 HB w/ D16, and I am overheating after 10-15 mins. Did the radiator test to eliminate head gasket issue, changed thermostat, replaced EGT sensors and relay switch still, no luck. Radiator cooling fan works when tested w/ direct line to battery terminal.
The lower hose never gets hot!! Help!!

 

Sounds like the radiator may be clogged up. Does the heater work? Does the system stay full before it starts to overheat? There could be a slow leak in the head gasket.

 

The heater works, System stays full and still overheats. Changed oil and there are no milky deposit and or smoke from the tailpipe on start up and when idling. I intend to reverse flush the radiator to see if there is a clog somewhere. Thanks in advance.