Engine getting hotter

[Jeepmedic46]

I just replaced my fan shroud on my auxiliary fan and installed a new ac compressor. The ac works great but the engine is running warmer. Running at about 230 to 240 at idle. Temp gauge stays in the middle while driving. At what temperature do I have to worry about the head cracking? I have the head that cracks.

 

[RCP Phx]

I'd be worried about it now, you even live where it's hot!

 

[Jeepmedic46]

I am worried. It’s not even that hot out yet. Any suggestions on what I can do? I read something about wrapping the fuel rail. Would that help?

 

[Leadfoot100]

wrapping the fuel rail isn't going to help your engine temps at idle. It will help to shield your injectors and fuel rail from a little bit of heat soak, so it's certainly not a bad idea, but you need to figure out your idle temps first.

Are you not getting your aux fan to turn on at high temps? also its worth checking your fan clutch to see if it's shot or not. at idle I don't get above 210 and the aux fan only kicks on when ambient temps are 85+

Edit:
To add, DEI makes a fuel rail shield kit for our jeeps. It's not a 5 minute install though.

https://www.amazon.com/Design-Engineering-010378-Injector-1997-2004/dp/B015NOKWQY

 

[Unclewolverine]

Wrapping the fuel rail helps with starting after heat soak. My opinion is that the 0331 head WILL crack, just a matter of when; there is nothing you can do about it. But it is odd that your jeep is running hot with the ac on, mine stays at a much more consistent 210 with the ac running since the e-fan is running all the time. Maybe time for a new fan clutch?

 

[Runnin'OnEmpty]

Here's another vote for a new fan clutch.
Even though they may appear to still work,
the clutch fluid will shear and wear out over time,
allowing for more slippage and less air flow.

Mine ran much cooler and the temps were more
stable with a new Hayden clutch. The Hayden is
designed to run about 5% tighter with less slippage
than the stock unit.

 

[Jeepmedic46]

I’ll check the fan clutch tomorrow. Thank you

 

[RCP Phx]

You didn't say what year, but at a minimum I would flush the entire system and get a new fan clutch and t-stat.

 

[Jeepmedic46]

It’s a 2000 sport. I’ll check it out later dealing with kidney stones this morning.

 

[Unclewolverine]

I've heard those stones suck, I feel for you. And yeah, if it isn't a reasonably new radiator then it's a very good chance it's partially clogged and your cooling was marginal before fixing the ac. Once upon a time I had an 01 sport that was an overheating nightmare. Two things were causing it: 1. There was a bunch of crap stuck between the condenser and the radiator, blocking the air flow, and 2. When I finally replaced the radiator and pulled off the tanks, about 75% of the tubes were clogged. I still have never found a reason xjs do this, only vehicle I've ever seen that clogs its own cooling system.

 

[RCP Phx]

I still have never found a reason xjs do this, only vehicle I've ever seen that clogs its own cooling system.

There is no difference between Jeeps and all the rest of the world, maintenance is your responsibility!

 

[Unclewolverine]

I've owned a lot of cars with much more neglected cooling systems and they never developed whatever that crap is that clogs up our radiators. The only plausible explanation I've heard is that dirt enters the system through the overflow tank; which leads to the question, do the sealed system xjs have the same problem with sludge in the cooling system?

 

[RCP Phx]

This is the first time I've ever heard that. I bought my 2000 XJ new in 2000 and never had that happen or even a problem till my tank cracked 18yrs later. If your using Kansas tap water that would definitely explain your finding!

 

[RCP Phx]

When I finally replaced the radiator and pulled off the tanks, about 75% of the tubes were clogged.

You may have also been experiencing a electrolysis issue, they develop easily and go un-noticed and are hard to detect, but todays motors have so many different materials used in them!

 

[Rob Mayercik]

This is the first time I've ever heard that. I bought my 2000 XJ new in 2000 and never had that happen or even a problem till my tank cracked 18yrs later. If your using Kansas tap water that would definitely explain your finding!

Some years back a popular mod to the RENIX-era XJs was to convert from the OEM closed-style system to an 91-96-style open type (often because the plastic pressure bottle/cap seemed to fail frequently and quality replacements were hard to source).

Also, my '92 that was open-style from the factory has never had that problem either as far as I can recall. I'm with RCP here - there must be something unique in your situation that's leading to what you were seeing.

 

[RCP Phx]

I'll add to that, I've owned a '87, '91, '93, '95, and (2)2000 XJ's and all have performed flawlessly.