WJCO
Meme King
Me too.
We have emissions testing here and it would fail the HC reading if I did that for sure. However, I got the OEM one back on already and process of elimination will let me know if it is the issue or not. We shall see.
WJCO's Build Thread, 1999 WJ
- Thread starter WJCO
- Start date
Me too.
We have emissions testing here and it would fail the HC reading if I did that for sure. However, I got the OEM one back on already and process of elimination will let me know if it is the issue or not. We shall see.
WJCO
Meme King
Still acting up. I will say the noticeable increase in the power with the OEM cat converter back on, I'm leaving it on even if I lose some ground clearance.
The issue is now (even with the new radiator), the temperature is also building at highway speeds while going uphill. It still acts up at idle at well, especially with AC on.
I've confirmed the fan and radiator are doing their job. All fans are working and the radiator is definitely cooling down the coolant from one side to another. The issue is that the engine is just getting too hot. At the water pump outlet, it's putting out 220-230 unless I rev it up. Once I rev it up, the temps drop, but then the issue comes right back. Thermostat is opening properly. Heat is working fine inside. I've bled the shit out of this cooling system. I did the block test twice yesterday and it passed. I also have no oil in the coolant nor coolant in the oil. And every time I've drained or flushed the coolant, it comes out clean as can be with no debris. I have no idea what to check next. Although I have installed two water pumps already, I may try a different brand since revving up the engine makes the symptom go away. I am also going to check all of the pullies to ensure something isn't binding up the belt (tensioner and belt are brand new). And I just installed my 3rd tstat yesterday for kicks, no change. And the issue occurs with the hood open, so hood vents won't help. I even put my old intake back on which draws air from a cooler location and it was no better. Oh and no leaks other than my heater core leak which comes and goes (even with heater core bypassed, issue was present though). Frustrating.
The issue is now (even with the new radiator), the temperature is also building at highway speeds while going uphill. It still acts up at idle at well, especially with AC on.
I've confirmed the fan and radiator are doing their job. All fans are working and the radiator is definitely cooling down the coolant from one side to another. The issue is that the engine is just getting too hot. At the water pump outlet, it's putting out 220-230 unless I rev it up. Once I rev it up, the temps drop, but then the issue comes right back. Thermostat is opening properly. Heat is working fine inside. I've bled the shit out of this cooling system. I did the block test twice yesterday and it passed. I also have no oil in the coolant nor coolant in the oil. And every time I've drained or flushed the coolant, it comes out clean as can be with no debris. I have no idea what to check next. Although I have installed two water pumps already, I may try a different brand since revving up the engine makes the symptom go away. I am also going to check all of the pullies to ensure something isn't binding up the belt (tensioner and belt are brand new). And I just installed my 3rd tstat yesterday for kicks, no change. And the issue occurs with the hood open, so hood vents won't help. I even put my old intake back on which draws air from a cooler location and it was no better. Oh and no leaks other than my heater core leak which comes and goes (even with heater core bypassed, issue was present though). Frustrating.
TrailHunter
Hooked
^^ thats crazy... there must be a blockage somewhere.
USMC Wrangler
New member
Holy crap! I’m frustrated for you. I hope the different brand of water pump makes a difference in a good way!
Snboarder113
Hooked
Booo.
Just spitballing, you have access to a wideband reader to check your AFR? Wonder if it’s leaning out and running hot. You’re pretty much out of things to fix at this point...
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Just spitballing, you have access to a wideband reader to check your AFR? Wonder if it’s leaning out and running hot. You’re pretty much out of things to fix at this point...
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WJCO
Meme King
That's my gut feeling but the coolant has been so clean. Since I've owned the vehicle, every time I've drained coolant for a repair, there is no debris nor rust.
Me too.
I have to check my scan tool but I was just thinking of that the other day. I do know my o2 is switching normally and I've never had any engine codes.
Snboarder113
Hooked
It’s grasping at straws for sure, but theoretically a particularly clogged fuel filter or weird reading o2/maf or even dirty injectors could possibly cause it to lean under certain circumstances. It would be extremely surprising but honestly you’re running out of options. How dirty is your engine? Read somewhere that cleaning the block of all dirt/ debris can drop it 10* not sure if that’s bs or not but sound plausible.
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TrailHunter
Hooked
Do you think the fan motor could be going out? Maybe it’s tired.... not pulling as much air as it should? Might be worth a shot to throw in a new one.
Strodinator
Caught the Bug
Napa water pumps have a metal impellor just be sure to buy a new one. The remanufactured ones are plastic. Maybe try pressurizing the coolant system to see if it can push through any possibly blockage? If heard of that working but never seen it done personally... I hate cooling issues, really hope you get it figured out.
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WJCO
Meme King
When I had it in the shop recently for my power loss issue, they checked fuel pressure. The tech knew his shit. They checked fuel pressure static, at idle, and under load and it was perfect. Also, vehicle runs great, awesome performance other than the cooling issue. As far as external dirt, it has a couple oil leaks but they've been there for awhile.
Fan motor is new. That is actually one component that I verified as failed from the get go. I had a new relay installed and intermittently the fan wasn't working when commanded. So good there. It still currently works on high and low. I also have a mechanical fan with a new fan clutch (second one I installed just to make sure). Temp readings and paper tests show air flow is fine.
I am definitely thinking metal impeller. But then again, I've put on 2 water pumps and issue is still there, so I'm not even sure that's it. Not a bad idea manually pressurizing the system.
My gut feeling is something is corroded somewhere internally and the coolant isn't moving where it's suppose to. It just makes no sense otherwise. I even ran the mixture at 80% water just for a test drive and it made no difference. So coolant type/mixture isn't applicable. I also just checked temperatures as both exhaust manifolds and both down pipes. There within a few degrees of each other which tells me it's unlikely a head or head gasket issue.
TrailHunter
Hooked
I say blockage then.... can pressurizing the system too much blow a seal?
WJCO
Meme King
Yes. I see radiator seals blow or tanks crack when a vehicle is overheating and the driver continues to drive it. I have a boroscope, so when I go to install the new pump, I may fish it around in there and see if I see anything.
Strodinator
Caught the Bug
You essentially don't pressurize more than the rating of the radiator cap. The system is rated for up to that so I wouldn't do any more. What's the cap rating like 14 lbs?
Edit: this is just from what little research I've done. I would definately look into it and see if it would even benefit you. Wouldn't want you to blow anything important
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jesse3638
Hooked
I just read all of this. I feel for you. I hate trouble shooting things like this. Especially when you're out of ideas. Hope you see something with the scope and can clear it. I'd be so mad at this point
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CharlesC
Member
Curious if you would be able to take off the cap when engine is cold and then run it up to temp to allow flow through the thermostat. Have someone behind the throttle to increase rpm while you look with flashlight through the opening and inspect if flow remains the same when the thermostat opens while keeping the rpm’s the same. May help in addressing if the thermostat is indeed opening, need burped or pump is failing.
Hope you get it fixed[emoji106]
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Edit: also, make sure to put the cap back on before the rpms drop when the thermostat opens or it will boil over.
Hope you get it fixed[emoji106]
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Edit: also, make sure to put the cap back on before the rpms drop when the thermostat opens or it will boil over.
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WJCO
Meme King
Not a bad idea. I was thinking of installing some clear tubing and doing something like that. I think my next step will be putting in a different water pump and really looking around inside the timing cover for corrosion and cavitation. I posted a pic last year of someone who had holes inside the timing cover from corrosion. I know there is at least some level of flow because the heater is working really well.
Also today, I pulled my control box off my winch which covers a good part of the grill just to see if it made a difference but it didn't.
Jsouder53
Hooked
Sorry to hear the cat didn’t fix the issue... I was almost certain that would fix it by the sound of what you were saying.
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HighwayTrout
Hooked
Is it possible the coolant is flowing too fast? Are you using an OEM pressure/temp thermostat?
Just tossing it out there. Might be a long shot. With one of my old cars I had unrestricted (no thermostats) and it would over heat because the coolant wasn’t in the radiator long enough. I restricted it and it cooled right down. Especially at idle with only the fan pulling air.
Also. Where is the oil and trans cooler located, in the tanks of the rad? Are the lines free of kinks and build up?
Hmm...Are you sure it’s no sucking air from the heater core leak? Fuck man. Feel for you. I hate these type of issues.
