Hey guy having trouble with my 4.0 s type overheating. I have installed new head gaskets (yes both heads were pressure checked and machined), new radiator, waterpump(metal blades),new exspansion tank, new thermostat, all new hoses. I have bled the sytem several time and I did it the way a tech that works at the dealership told me to do it and still no luck. Does anyone have a cooling sytem map or idea what my problem is? I also need help har reseting my pcm cause it went into failsafe mode the other day.

 

There's quite a bit of what you want in JTIS if you look.

No point in the PCM reset. Read any codes, including pending codes, for clues. You may need your own OBD tool, in which case get one with live data such as the elm327 - about $15.

 

How did you bleed the cooling system - there is a specific procedure for the 4.0 engines. Also, how old is your battery? +1 to JagV8 regarding the hard reset of the PCM & JTIS - you need to first determine the cause of the PCMflagging failsafe mode.

Finally, are you sure the head gaskets were replaced properly? This is very intensive, especially dealingwith the timing chains, tensioners, etc - many ways to "miss a step" that can be costly.

 

might be worth double checking the thermostat, i have bought failed ones in the past, also as abonano says, the 4.0l are notoriously difficult to bleed so i'd double check that bleeding procedure.

 

Battey is about 1 1/2 years old now and I replaced timing chains and tensioners head gasket done to spec not my first rodeo been working on cars 15+yrs. As far as bleeding the system I was told to turn the heater full blast, let it get to operating temp then shut off the engine and let coolthen remove the cap check coolant level the start engine then loosen the bleeder on the expansion tank and blled it untill a steady stream of coolant comes out then shut it of check coolant top off if needed the test drive it. Jag V8 I have an obd2 code reader and the codes are as follows p01572,p01586,p0102'and p0113. any help would be greatly appreciated and thanks for the replies.Oh and its my third thermostat and it will even run hot with a gutted thermostat.

 

Have to check Jtis again must have missed the info on there.

 

Codes are also there (and here in stickies as well). Note that they are a letter and 4 digits, delete any leading 0 that makes them longer.

Be sure to look codes up in Jag's doc ONLY as other sources have many errors! Plus, jag give known possible causes.

For those ones, worth checking they all come back (or which do first) when cleared.

 

I hope you didn't take offense regarding asking if the job was completed correctly. Many "indy's" state - "Oh yeah, we can do that" and screw everything up. (That's why I do my own work as well) - before starting the bleed procedure - did you fill up coolant through the top of the thermostat housing and tighten that cap down to 9Nm (6.7 ft lbs)?

Also, another point - did you replace the water pump with plastic or metal fins? I know metal fins are the upgrade (which I used - there is a debate regarding their effectiveness vs. plastic fins) - when you pulled the water pump - was everything intact? (plastic fins) quite possibly you might have something lodged in one of the cooling hoses causing the overheating issue..

I upgraded the thermostat housing to aluminum as the plastic housing is notorious for failing... one last point I want to share.. I found that during the bleeding procedure - you have to let the car cool down a while (at least an hour or two) before starting her up again to acheive the best effects.

When I bled my cooling system - it took 3 - 4 times before all the trapped air was fully purged from the cooling system. Thanks

 

+1 on the water pump...... I'd want to get that puppy off and make sure the impeller is intact. I'd guess it suffered an overheat or two with the blown headgaskets.

Cheers,

 

You have a new waterpump and a new thermostat.

As you know, simplisticly, cooling only needs three things:

- sufficient coolant
- thermostat opening
- coolant flow

So ...

How are the hoses leading to and from the radiator? Are they both getting scalding hot?

If the engine is run with the cap off, can you see ripples in the tank that indicate coolant flow?

Does the overflow puke coolant when the system is full and the car is turned off after running? That one is a sign of crossed bleeder and overflow hoses at the expansion tank. Not knowing your car, the bleeder from the radiator should be at the nipple lower than the overflow to the overflow tank. That's because the overflow is released into the gap at the top of the pressure cap.

 

Not offended at all abonano just alil pissed with this car. It has a new water pump one with metal blades and one with out old one had plastic blade and they were all intact car ran hot with both new pumps and I did fill it from the top of the thermo housing. I will admit thought that I only went through the bleeding sequence twice. once then again after cool down. I'll try 3 -4 if I can get it back running it went into failsafe mode it will spinover but won't crank.and I'll check all the hoses. I bought it with the blown headgaskets and it blew them because the hose under the intake manifold was corroded and the plastic pieces could be lodged some where but I have flushed the cooling system several times.

 

On the thermostat housing check the oring in the cap. A easy way to check it is to squeeze the lower radiator hose after car is heated up and turned off. Lower hose should be stiff and extremely hard to squeeze. If not you have a leak somewhere, likely at thermostat housing cap, the one you take off with allen wrench.