I maybe getting paranoid or I could have a problem - saw the post on overheating and blowing head gasket.

Have a 2002 Stype 3.0 with 65K miles - the temperature gauge has never exceeded the middle but when I open the hood - the engine seems hotter than usual after say a 20 mile drive. The coolant level is fine - no signs of boiling over - never had any leaks - don't have to top off or anything. When I check the engine bay with a laser thermometer I get range of hot temperatures 180-200-220-270-300 depending on what I point it at. Is there anything specific I should measure the temperature directly? What can I do to determine if I have a problem or not?

 

Do your cooling fans run after you shut off the engine?

 

Obtain a good OBD II reader w/ live data and you can see the coolant temperature "real time" - forget the temp gauge - that thing won't budge past the 12 o'clock position until the coolant temperature is out of the ball park.

The 21st century version of the "idiot gauge"...

 

+1. And if you see readings over about 215 F you have a problem.

 

+1 e.g. elm327 start at about $10 from amazon

 

Yes I do have one of the Bluetooth ELM 327 knockoffs - has a difficult time reading the real time data points (think has to do with the protocol in the older MYs). Will check and report back. I don't believe I have heard the cooling fans come on anytime recently but I haven't been looking for it. BTW - no MIL either.

 

Well downloaded the Torque android app for 4 bucks - worked really well with the knockoff ELM scanner (as opposed to the half a dozen or more OBD software packages I tried before). Anyway I was only monitoring the coolant temperature till my tablet battery died (don't have a car charger). The max temp after 45 min of start and stop driving was 210 F (real-time scanning) and stayed at that level. No error's on scanner that I could see - though I was only able to briefly check it before battery died on tablet.

Don't think the cooling fan came on - is there an easy way to check if it is working? Guess I need to drive longer distances and more time and check again. Is there any other things I should be looking for?

 

I have one radiator fan - the blades will not spin by hand with engine off. Is it supposed to or is it seized. Is there a clutch or something that has to be disengaged?

 

210F sounds quite normal after 45 mins of driving. I would think the fan should be running at that point, even at 210F

 

If you warm the engine up, then let it sit idling you should see the fans cycle on and off after a few minutes, especially on a warm day.

 

Is it normal for the temp gauge to be a hair over the 12'oclock position? I have an STR and mine is usually a hair to the hot side.?

 

Ignore that gauge unless it reads VERY HOT in which case shut engine off immediately. It's the stupid kind of gauge becoming more common on cars and smooths out the reading to such an extent it really only has 3 values (too cold, normal and close-to-or-actually-ruined-engine-hot).

With an STR you must have the redesign cluster so look up ETM (see my sig, please follow both items).

 

Well now that I think of it - I don't really recollect when I last heard the cooling fan run. Didn't come on when I shut car off and the temp was 210.

Can anyone confirm that one can spin the fan blades by hand with the engine off (well just make sure that the car isn't hot).

If so I can start looking around for a new fan.

Will be away for the next week or so so won't have time to investigate - will have to wait.

 

All it is, is an electric fan and therefore you should be able to spin it by hand.

If you can't spin it and it is not obstructed by anything then it will need replacing.

 

I have the 4.0 V8 engine. I can spin my fan by hand. When the engine is running around 200F or so - the fan is running

Hopefully, this will point you in the right direction...

 

Thanks for the confirmation - will start looking around for a replacement fan.

 

I bought an STR with known cooling / overheating issues because the previous owner had basially been told by the Jag dealer (Reedman in Langhorne, PA), that the car had blown a head gasket, and that it needed at least a head gasket, OR possibly a new engine.

First thing I did was fire it up with an ultragauge plugged in. That "idiot" gauge on the 03 Str didn't start coming off of center till the car was at nearly 240 degrees!!!!!!

Second thing I realized after much discussion with a few Jag techs and others. These cars will not let you blow a head gasket. They will literally turn off before temps get to damaging levels.

AS for mine. A thermostat, and a water pump for good measure later, and I've put 1600 miles on it while slowly sorting out other issues.

Take care,

George

 

I wouldn't rely on the V8 cars to stop an overheat. I understand only the V6s will shut down cylinders to stop it.

 

Yes, they will turn off because of loss of compression due to dropped valve seats. Been there, and it is not a good place.

 

From my discussions with two jag techs, the 4.2 will not let you hurt it. It basically goes into restricted performance / limp mode, and then shuts off. The 4.0 may have, actually it probably will.

Take care,

George