BryO

Driving the car Sunday morning and she starting looking like(from what read on the gauge) she was getting hot. Pulled over and fans not coming on. Went home and pulled the fan relay out of the spare 44. Fans working fine. All is well....

Driving her to work this morning and turned around because, yet again the gauge is right at the tip of the red. Hit the defroster button and the needle dropped to below the third line. Strange.

While driving home, I noticed when I would hit a dump, big dump the fuel and temp gauge needles would jump around. Left the defrost on to keep both fans running. No leaks from hoses, nothing on the ground under her, year old radiator/H2O pump. Thinking the worse, but no water in the oil nor reverse.

mazdaverx7

was the coolant boiling in the expansion tank? are you thinking there is an issue with the electrical system causing a false reading of the gauges?

River

could be a variety of things man.


First, clean all your grounds. That should be a given. Do it once a year (use baking soda and coke).

Second, Check your radiator cap and make sure it's holding a seal. Some places will even check it for you for free. (hence, do the free stuff first).

Third,: Bleed your system/flush.

Fourth: (if the radiator cap is good),and you've bleed the system check your thermostat.

There is of course more things to check, but this seems to be a good order to tackle first.

also, I would hope you've changed out your dme temp and block sensors out and replaced with new if you haven't done so already...

nasty9er

i forgot to bleed the heating system when i did my coolant change and the car ran fine until i turned on the heat this winter and then it started to want to over heat on me again so make sure when you bleed it that you run your heat on full blast and bleeding takes more then one try to get all the air out

my $0.02

mytrplseven

It is recommended that you jack up the driver's side of the car when doing the bleeding to get the last little bit of air out of the system. I re-did the front of my motor: belts, rollers, WP, seals, gaskets, etc and when I bled the system I jacked the car up and car has been running solid on the temps with and without the a/c on.

zerMATT951

+2 on bleeding and checking the cap. It only takes a tiny bit of air in the system to make the temp gauges on these cars jump all over the place. The fan temp sensor is on the radiator, so the fans may still cycle normally (assuming the relay is good), but the gauge can do crazy stuff if there's a little air in the head by the temp sensor.

And yes, a bit of an incline or jacking up the front a tad, and heater set on FULL HOT is required.

BryO

Thanks for the info.

Thermostat will be here today and ordered the switches this morning and get them from a local shop.

I am willing to bet I have air in the system, like you guys are say. Never read anything about jacking up the drivers side, so I bet after replacing all the hoses air is there.

Will post the results tonight.

Hollywood D

I had to bleed a little coolant out of my system on a job I was doing a while ago. I refilled it but obviously had air in the system because i loosened up a hose to drain some of the coolant out. Temp gauge was acting funny after that and reading higher than normal.

River

I've done it both ways with the bleeding (jacked, and level).

Never noticed a difference.

To each their own though. I swear, each of our cars have different personalities on what they like done though, lol!

ArcticSteve

While driving home, I noticed when I would hit a dump, big dump the fuel and temp gauge needles would jump around.

If your negative battery cable to bell housing is original then get a new one.

BryO

Here is a wrench in things...

Drove it to work this morning to check out to see if the new parts and the flush helped.

Well, no. Not boiling over, just get hot as hell and lose of power and a sputter when taking off from a stop. Feeling a head gasket going. I will check the fluid level at lunch today. But with the lose of power, sputter from a stop and the heat getting high but never overheating leads me to believe a head gasket going.

JimV8

In the OP you said no fans on but after checking they worked. If the fans won't run without the defrost on surely that's an electrical issue. Does it overheat at 60mph in 5th?

BryO

fans are all working now at low and hi speed. I replaced the relay, Thermo switch and both temp switch's.

in 5th 60 to 70 sitting at the 3rd line without moving. Stop and it goes right to the edge of the red and sitting there till you start to move again and them down to the third line again.

Rare that it will drop below the third line now. Popped the hood and I can hold the top hose. It is hot but I can keep my hand on it for a while. Same with the expansion tank. I can put my hand on it and leave it there. That is why I am thinking a head gasket going.

ZR8ED

If you think the head gasket is leaking, then take a look at the tailpipe for white smoke. Exhaust should have a sweet type of smell to it. After a long drive, it may also still be putting out moisture through the tailpipe that you can feel if you put your hand in the stream.
It is not an absolute test, but a good indicator, and costs nothing.

River

+1 on the white smoke. Pull your spark plugs and see what they look like. Plugs tell all.

I'll assume yes but, change the water pump within the last 70k? (belts every 35k or three years, pump every other belt change)

check to make sure you can feel coolant running through all your hoses.



Also, you'll hate to hear this. Radiator? The radiator can develop "scales" that block coolant and cannot be flushed out. You have to replace the raddy at that point.

have you done everything on Clark's?