Car Overheating at random times

[dac99011]

Hello fellow MM enthusiasts:

History - I have a 2003 MM all stock with 95k miles on her. Last July with the a/c on my temperature gauged went from the normal operating range to the H on the temperature gauge in about 10 seconds. I pulled over and the cooling fan was not running at that time. I cranked up the heater (no ac) and limped her along 2 miles to the FORD dealership. This checked her out and could not find anything wrong. I suspect the Fan assembly that includes the relay could be bad. Before I invest in the Fan/relay assembly ($450) is there anything else I should try?

Thanks.

[dac99011]

I should have mentioned this happened again today! It is intermittent.

[ctrlraven]

My fans totally stopped working and I went straight to the dealer, they said the fan relays or relay module was bad, $450 for the part and $200 for labor.

When is the last time you had a coolant flush and t-stat replacement?

If you get the fan/relay assy, buy it and install it yourself. I wish I had been able to do that but I was stuck on the other side of the state and away from my tools.

[dac99011]

While it was at the dealership, they burped the coolant system. I had the entire coolant system flushed about 10k miles ago (more than 1 year ago) and used the GOLD ford antifreeze. I have not changed the thermostat.

When the issue occurs and I pop the hood, the fan is not running. Even if I turn on the A/C which should also engage the fan, does it not run. If I turn off the car and turn it back on, no issues.

Do you think I should change the thermostat in addition to the fan/relay?

Thanks!

[dwrwebb]

I just started having this same problem too...The overheating seems random, and often a simple shut-off, and restart of the engine "fixes" it...I hear the fan running, and putting the heat on full blast seems to have no effect, although it is interesting to note that this morning it happened again as I was driving along, and as I saw it rise (for no reason I can tell, although obviously there is a reason!), I turned the heat on full blast, and it wasnt even close to warm, but it had been about 5-10 minutes prior to that. I shifted to neutral and coasted to a neighborhood up the road, but as I shifted back into drive, the temp dropped back to normal again. I have checked the obvious things (coolant, oil, etc.) FYI-The thermostat is only a month or so old. I got a new one when I got my new engine.... I havent had any problems with anything since my new engine until yesterday morning when this first happened...

[RF Overlord]

I turned the heat on full blast, and it wasnt even close to warm, but it had been about 5-10 minutes prior to that...but as I shifted back into drive, the temp dropped back to normal again. That's the clue right there. There are only a couple of ways this can happen:

1. Thermostat stuck/sticking.
2. Air in the system.

Obviously burping the system is the easiest thing to try first.

[dwrwebb]

Thanks. I'll give it a shot. It just seems odd that there would be air in the system. How dies that happen? Ford put the new t-stat on when u got my new engine about a month or two ago, and this priblemjyst started within the past few days. Thanks for your help

[SC Cheesehead]

Thanks. I'll give it a shot. It just seems odd that there would be air in the system. How dies that happen? Ford put the new t-stat on when u got my new engine about a month or two ago, and this priblemjyst started within the past few days. Thanks for your help

Prolly happened with the t-stat change.

Try parking the car with the nose pointed slightly uphill, that will help get any blocked air to move toward the vent.

[fastblackmerc]

Thanks. I'll give it a shot. It just seems odd that there would be air in the system. How dies that happen? Ford put the new t-stat on when u got my new engine about a month or two ago, and this priblemjyst started within the past few days. Thanks for your help

It happened because some Ford techs don't know how to burp the MM's cooling system.

[fastblackmerc]

Hello fellow MM enthusiasts:

History - I have a 2003 MM all stock with 95k miles on her. Last July with the a/c on my temperature gauged went from the normal operating range to the H on the temperature gauge in about 10 seconds. I pulled over and the cooling fan was not running at that time. I cranked up the heater (no ac) and limped her along 2 miles to the FORD dealership. This checked her out and could not find anything wrong. I suspect the Fan assembly that includes the relay could be bad. Before I invest in the Fan/relay assembly ($450) is there anything else I should try?

Thanks.

If your fan is not coming on when you turn on the A/C then you have either, a bad fuse, circuit breaker or relay, bad fan assembly or a wiring problem.

[dac99011]

UPDATE: I purchased the same FORD OEM fan/fan relay through ROCKAuto for $350 and replaced. The next test drive, the temperature gauge pegged on HIGH(note the car was cold temperature before driving).

I went and purchased the Thermostat from FORD, replaced, burped coolant system and voila...it has never happended since.

I believe the Thermostat was sticking because the car would only briefly overheat (1-5 seconds) when the car would first heat up..making me believe the Thermostat was stuck initially.

Thanks for the advice!

[dwrwebb]

Thanks. I'll give it a shot. It just seems odd that there would be air in the system. How dies that happen? Ford put the new t-stat on when u got my new engine about a month or two ago, and this priblemjyst started within the past few days. Thanks for your help


Here is my final analysis...there was indeed air in the system. Also, the reservoir boiled over at some point (I could see signs of "blowback" on the passenger side cam cover), which likely lead to additional overheating instances (low coolant...). I topped it off/burped it, and all is well as of now...knock on wood. Anyway, It appears somehow my lower spoiler/air dam, or whatever the official technical term is, seems to have split, and I got a replacement. I figured this may well have contributed to the problem as well. I don't even know how that happened, unless it started when my wife backed the Black Beauty into a drainage ditch...That was a while ago, but I think perhaps that started a small crack, which eventually tore more until it was just a giant loose flap of plastic under my car....

Anyway, thanks to everyone for your help!!

[Billboard]

I had an intermittent no heat along with the engine temperature gage rise issue. Also I could not idle the car for very long without the engine getting hot. I followed the coolant system purge procedure found in another thread, and now all seems back to normal. My car is a recently purchased 2003 300A with 70k miles.

[SC Cheesehead]

I had an intermittent no heat along with the engine temperature gage rise issue. Also I could not idle the car for very long without the engine getting hot. I followed the coolant system purge procedure found in another thread, and now all seems back to normal. My car is a recently purchased 2003 300A with 70k miles.


:welcome:

So, now all is well?

If the problem re-occurs, try burping it again, Marauders can be stubborn relating to air in the cooling system.

[Billboard]

So far all is well, my fans have always been kicking on, so I believe it was just a coolant purge issue. I idled the car today for about 15 min and it did not even give any hint of getting hot. Before the I did the purge/re-fill five min of idle would send the temp Gage north.

[RF Overlord]

Welcome, Billboard. Nice to have another member from MA.

[Billboard]

Welcome, Billboard. Nice to have another member from MA.

Thank You, so far this has been a great group of owners. Right now everything on my Marauder is working, knock on wood, not bad for a 9 year old car.

I will be heading to Epping NH soon for the 1/4 mile. Probably a Friday night, I will try to get as much notice as possible. Sense I bought my 300a I have yet to see another Marauder on the road.

[RacerX]

Let me know when you go. I'm in Nashua, NH. I'm tearing my block apart shortly, but, always willing to hang, take pics, talk shop... :beer: