Why is my fender overheating?!

[Anak]

A backwards running fan crossed my mind as well. IIRC the rotation changed with the belt routing change that occurred in '96. It would be easy to get the wrong parts. In fact, I think I have seen where someone wound up with wrong parts from an auto parts store because the manufacturer (or remanufacturer) couldn't keep the differences straight. Certainly worth a check to see which way the air is moving over the radiator.

From the pic it would appear the fan shroud on that side is intact, at least at the top. Is it good all the way around?

I can't think of any way the HVAC system would get air into the inner fender, unless some big hole has been made in the firewall/lower cowl.

Exhaust would be a similar puzzle.

If none of the above pan out I would remove the outer fender and see if that sheds any light on the situation. At the very least that should put an end to the air blowing in through the square hole, and at best you should be able to find the source of the air and proceed to chase it further back from there.

Best of luck and let us know what you find.

 

[techno1154]

Hey! I am on to something here :idea: . Pull the fender off and look for hidden objects such as an additional heat source or hot air duct and let us know what you did to prevent that problem from reoccurring . I know your finding will help many of fellow XJ owners.

That was my attempt at satire.

My recollection of XJ'S with their fenders removed it is close to impossible to fabricate something that will fit in there with a fan and heater to heat the air and blow it with sufficient velocity to heat the fuse box to the point of relays malfunctioning,...and besides it appears that it is only the relay that controls the fuel pump along with several other ignition related equipment.

Could it be the original poster is so fixated on the fuel pump that he misses or completely ignore the other accessories that are not working?

A backwards running fan crossed my mind as well. IIRC the rotation changed with the belt routing change that occurred in '96. It would be easy to get the wrong parts. In fact, I think I have seen where someone wound up with wrong parts from an auto parts store because the manufacturer (or remanufacturer) couldn't keep the differences straight. Certainly worth a check to see which way the air is moving over the radiator.

From the pic it would appear the fan shroud on that side is intact, at least at the top. Is it good all the way around?

I can't think of any way the HVAC system would get air into the inner fender, unless some big hole has been made in the firewall/lower cowl.

Exhaust would be a similar puzzle.

If none of the above pan out I would remove the outer fender and see if that sheds any light on the situation. At the very least that should put an end to the air blowing in through the square hole, and at best you should be able to find the source of the air and proceed to chase it further back from there.

Best of luck and let us know what you find.

If the fan was turning in the wrong direction would it not pull hot air from the engine compartment and blow it through the radiator? , and would the engine not overheat?

 

[Digger87xj]

That hole is there for the RHD application. Unused for LHD

CPS is your stalling problem, not heat on the PDC

 

[voudoux]

If the fan was turning the wrong it would push air through the radiator and out every other hole in the fan shroud. But I am not sure it would quickly overheat as it would pull fresh cooler air from under the jeep. Moving down the road most cars with air use clutch type fans that sort of free wheel unless needed the car or jeep moving through the air does the cooling. This air moving the wrong way could account for the hot fender if there are holes in the right places. I don't have a clue why it stalls, as I said possessed.

 

[Demonoid369]

I actually have tried to cook an egg. Use foil and enjoyed a Sunnyside up egg thank you very much

 

[AIbandit]

Really no nomination? What's wrong Naxja?
Nominated.




There is absolutely nothing in that fender your heat is coming from sunlight on the body. ( A smaller example of why you don't leave a dog in a car.)

 

[IslanderOffRoad]

I clearly said the fuel pump was not running, repeatedly, so who is the one not listening? The CPS, and every other sensor, DO NOT prevent the fuel pump from running/priming as it should. They prevent the engine from sparking. I do not have any spark problem.

I never asked why it died, I asked why this part is getting too hot. Just because I don't have a bunch of posts here doesn't mean I'm an idiot, it's pretty easy to tell when the fuel pump isn't running. I'm not guessing, I know that for a fact. I could hear the fuel pump not priming as it should, as I have already explained. Additionally, I'm pretty certain the fender should not ever reach 170+ degrees at idle from a cold start after 10 minutes, clearly, this is not a sensor problem.

Every time I've had a cps go bad it's been initially mis diagnosed as a fuel pump issue.

 

[IllianaXJ]

XJ underhood temp has always been enough to nicely cook a burrito or hot pocket. Matter of fact I enjoyed wings cooked in a foil pouch under the hood on my last wheeling trip. Heat is not your issue.

Check/replace your auto shutdown relay.

 

[Bent]

Really no nomination?

I was getting there. Sometimes it takes awhile.

 

[AIbandit]

To be honest this isn't the first time I've heard of fenders burning.

 

[Number21]

Now I remember why I don't post on forums, a bunch of know it alls trying to have a popularity contest or increase their post count because somehow it makes them feel superior.

FYI - I checked the fuel pressure and the spark when it wouldn't run, it sparked, and the fuel pressure was low, thus, I can say with 100% certainty the fuel pump was not running correctly, and the CPS is not ever a cause of that. Neither is any other sensor. Beyond that, I found a receipt for a new CPS install about 20,000 miles ago, and a new fuel pump about 10,000 miles ago. This XJ has been very well maintained by professionals for most of it's life.

Like I said, I'm not an idiot, and I'd be willing to bet I know more about XJs than several of the people posting here. I've been driving them since before some of you were probably born.

Secondly, it's not the sun, do you really think I am that stupid? I've been testing it at night, in the dark, when it is cool. The passenger fender heats to over 175, though, I'm betting few, if any of you have ever actually bothered to measure the temperature of your body panels. The fact that my driver side fender, where the exhaust is at, is a good 30 degrees cooler than the passenger side, says something is wrong. Additionally, the battery is over 150 degrees, and that is not how they are supposed to run. That will kill a battery in short order. Yes, you can cook food under the hood of almost any vehicle, if your body panels get so hot that they burn you in the dark, something is wrong with your old POS Jeep, they did not come from the factory that way, they are not supposed to run that way, that is not normal. There's a difference between running warm and overheating.

I appreciate the one or two of you that actually tried to help, thank you to those. To the others, get a f***ing life, you're not the expert you think you are. I'm not going to bother any further with this thread, too many attention whores with blatantly bad advice simply trying to increase their post count while totally ignoring the input from the one person that actually has their hands on the vehicle. Obviously school is out and the children are bored...

 

[AIbandit]

A lot of people tried to help you, your focus is in the wrong spot. My fenders are cut open there's nothing back there that can cause heat.

CPS issues tend to be intermittent. Relay issues can be too. So can fuel pump issues.

If your battery is excessively hot maybe you should look at wiring.

If you really think it's your fender you can cut it open like mine and see nothing.

It's 90 degrees out right now and my car that was shaded most of the day and not ran at all is reading 160* at the fender. 170 doesn't seem so impressive when you add engine compartment heat.

 

[Number21]

A lot of people tried to help you, your focus is in the wrong spot.

Actually you have that backwards. I did not ever ask why my jeep died or for anybody to diagnose anything other that why so much hot air is blowing around the fender/battery/fuse box area. That is NOT normal no matter how hot XJs normally run. The fact that my other fender, even though it is closer to the exhaust runs much cooler, also suggests something is wrong. I did not say the fender was causing heat, I said hot air is blowing through it when it shouldn't be. The source of the heat is the hot air from the radiator, nothing electrical. I was very clear about that.

CPS issues tend to be intermittent.

How frequently do CPS issues cause low fuel pressure and allow the engine to keep sparking?

If your battery is excessively hot maybe you should look at wiring.

As I said repeatedly, it's not a wiring issue. The battery is hot because of the excessive hot air being blown over it. It's not hard to see that when you are actually here looking at the vehicle, as none of you are.That's why I told you that is what is happening, since you aren't here to feel it yourself. Just take my word for it. If you don't like taking my word then there is really no reason for you to bother posting here.

It's 90 degrees out right now and my car that was shaded most of the day and not ran at all is reading 160* at the fender. 170 doesn't seem so impressive when you add engine compartment heat.

Is your passenger side fender approximately 30+ degrees hotter than the driver side and the hood?

 

[AIbandit]

Is your passenger side fender approximately 30+ degrees hotter than the driver side and the hood?

Ahh no, It's 131 degrees, so only 29 degrees cooler.

 

[AIbandit]

For the sake of being thorough I checked my F250 too,
151* on one side 105* on the other, demon magic.

 

[Number21]

To be honest, the temperature of the body when the vehicle has not been running and sitting randomly in the sun is not relevant to anything. I have been measuring the temperatures in the dark or in the shop, where the sun cannot influence the results.

 

[AIbandit]

Well, seems the next logical option is to cut it open to find your source. Or on amazon they have inspection cameras for your phone at <$20.

 

[voudoux]

Great post!!

 

[jeep ride]

How can you be sure the hot air is coming through the square hole?

 

[voudoux]

Number 21 did you read my post? There are only so many sources of the heat you are talking about ,work backwards from the heat sources . I think if it were electric it would have fried by now. Good luck,I have no idea about the other problem only the heat one. May be possessed?
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