Overheating problem
- Thread starter Dvaniwaarden11
- Start date
At 2500rpms my oil pressure gauge seems to read correctly according to the 10psi per 1k RPMs right?
I guess I’m just really hoping it’s not engine related. This thing is brand new and that’s going to be a rough conversation with my mechanic. I believe it’s still under warranty but still not fun after having this guy jump through hoops trying to help me fix this issue.
Granted I’ve fixed everything aside from the engine at this point. All roads lead to that and although sometimes the cooling system could get above 210, it shouldn’t be around 220….
Man I just want a normal fucking Jeep. Lol
I’m gonna buy another fuel pressure sender to make sure I’m getting accurate readings but I’ll talk to my mechanic tomorrow morning.
I guess I’m just really hoping it’s not engine related. This thing is brand new and that’s going to be a rough conversation with my mechanic. I believe it’s still under warranty but still not fun after having this guy jump through hoops trying to help me fix this issue.
Granted I’ve fixed everything aside from the engine at this point. All roads lead to that and although sometimes the cooling system could get above 210, it shouldn’t be around 220….
Man I just want a normal fucking Jeep. Lol
I’m gonna buy another fuel pressure sender to make sure I’m getting accurate readings but I’ll talk to my mechanic tomorrow morning.
AC was off since I don’t run windows. But I can test it with the AC on and report back.
So got my Bluetooth OBD.
After driving for 30 minutes in 90 degree heat this was the reading. The tach is accurate but I don’t have a speedo for the 35s yet so the speed is about 4-5 mph faster than what the pcm reads. 230 is still way to hot for what I’m comfortable with.
The gauge on my dash showed a little bit over 210 so I’m assuming that’s just how they were made back in the day and then they would jump to the red when you started overheating? Not sure. Either way, the fan that my mechanic installed helped a little bit but not much.
He wants to put a bigger fan on there to see if that will help. I doubt it but he’s doing all this work for free so I’m not opposed to it.
I’m at the point where I think my root cause is the radiator not keeping up. It is a denso which a lot of y’all have said would be sufficient, however at freeway speeds it still gets hot. If it hit stop and go traffic it cools back down to 208-210. I don’t want to go the route of custom large radiator shit because then I’m looking at $600+.
The pump is an AC delco that was installed a few weeks ago. Thermostat is a 195 installed 3 weeks ago. Denso was installed a month ago. Non clutch fan (spins 1:1 with motor) was installed 3 weeks ago.
Any more ideas? Lol
After driving for 30 minutes in 90 degree heat this was the reading. The tach is accurate but I don’t have a speedo for the 35s yet so the speed is about 4-5 mph faster than what the pcm reads. 230 is still way to hot for what I’m comfortable with.
The gauge on my dash showed a little bit over 210 so I’m assuming that’s just how they were made back in the day and then they would jump to the red when you started overheating? Not sure. Either way, the fan that my mechanic installed helped a little bit but not much.
He wants to put a bigger fan on there to see if that will help. I doubt it but he’s doing all this work for free so I’m not opposed to it.
I’m at the point where I think my root cause is the radiator not keeping up. It is a denso which a lot of y’all have said would be sufficient, however at freeway speeds it still gets hot. If it hit stop and go traffic it cools back down to 208-210. I don’t want to go the route of custom large radiator shit because then I’m looking at $600+.
The pump is an AC delco that was installed a few weeks ago. Thermostat is a 195 installed 3 weeks ago. Denso was installed a month ago. Non clutch fan (spins 1:1 with motor) was installed 3 weeks ago.
Any more ideas? Lol
JKP
TJ Addict
Yep, too hot for the conditions.
You need to get an oil pressure test gauge. Factory gauges are damped down to prevent owner panic and complaints as you found out with the temp gauge.
Your pic showed less than 20 PSI, so if you were at 2500 RPM you should have been at 25 PSI or more. A new motor should probably be indicating 40 PSI or more on the factory gauge.
I would guess your oil pressure is actually less than the dash gauge indicated.
For a point of reference, my 300K mi YJ shows right at 20 PSI or so at hot idle here in GA, IIRC. I'll check it tomorrow as it's going to be mid 90s or so.
You need to get an oil pressure test gauge. Factory gauges are damped down to prevent owner panic and complaints as you found out with the temp gauge.
Your pic showed less than 20 PSI, so if you were at 2500 RPM you should have been at 25 PSI or more. A new motor should probably be indicating 40 PSI or more on the factory gauge.
I would guess your oil pressure is actually less than the dash gauge indicated.
For a point of reference, my 300K mi YJ shows right at 20 PSI or so at hot idle here in GA, IIRC. I'll check it tomorrow as it's going to be mid 90s or so.
JKP
TJ Addict
Check the hot idle pressure and then at 2K and 3K when it's up to temp.
Also, do you know what oil the mechanic put in it? It needs to be a Xw30 or Xw40. None of the new thin 20 weight oil.
Also, do you know what oil the mechanic put in it? It needs to be a Xw30 or Xw40. None of the new thin 20 weight oil.
JKP
TJ Addict
Here is the oil pressure spec from the FSM. A new motor should have great oil pressure.
Update to your question.
I drove with the AC engaged on the highway and then in stop-and-go traffic.
Highway:
ECTs went from 194* with the AC off to 199* with AC on while cruising around 70-80 mph.
ECTs peaked at 204* going up a lengthy incline around 70 mph and then dropped back down to 199-201*.
Stop-and-go:
ECTs peaked at 203* and quickly dropped to 194-195* once I was consistently driving for 1/4 to 1/2 a mile.
(ambient temps were 97*)
Last edited:
JKP
TJ Addict
Here's the YJ oil pressure. 90 deg temp, AC on, 195 thermostat, 0W-40, approx 300K mi. 20 PSI hot idle. At 2K it was about 45, and at 3K it was just under 50 as shown in the pic. The YJ temp sensor is in the back of the head and it's a real gauge vs computer driven. This is full temp for it.
We’re always bragging on our TJ’s, but perhaps the YJ was the last real Jeep…
Real Gauges > Idiot Guages.
JKP
TJ Addict
I do prefer the gauges in the YJ.
I actually drive around with the Bluetooth OBDII hooked up in the TJ with gauges setup on the phone so that I get undamped data from the sensors. Except of course for the oil pressure. In the 06, the oil pressure gauge is just really an idiot light...
If you can stand a primitive, short wheelbase early model, you can get a real Jeep with real gauges!
My first post on this forum so be gentle...
Being the engineer I am I found a solution(s) x3:
1) Jeep made a special 6 blade fan for the TJ. Chances of finding one of these is slim. I found about the fan from Jeep and I wrote an article and install and pics. Only need to remove your fan. the 6 blade drops in.
I was a Super Mod on a major Jeep Forum in the US with 13,xxx active Jeepers and I had about 40 mods under me. So I posted my write up and it got forwarded across the US. About 3 mo later I started getting tons of mail from across the US asking me where can that 6 blade be found, all the dealers were out of stock.
YOU may ask your dealer...
Some additional info.
2 0 The 6-blade solved my problem....Until I installed my SC, the my Jeep heated up like a Senior boy in HS who had a date with the Homecoming Queen and its his first ever date.
I installed a pair of Dodge hood vents from a Dodge that was being sold at that time with a SC.
3) That + the 6-blade + Vents + Cold Air Intake.
I tested a LOT of CAI, I lived in Phoenix AZ where temps are normal even in the 120s and on trail runs in the Sonoran Desert 130s: Bottom line is CAI does not work because no one knew how to build it. A friend of mine bought a Jeep CJ at an estate sale. Jeep had sat up for over 10 years and it not running, flat tires, everything dead. He called me and said I needed some help so I ran over.
I lifted the hood and what did I see...FOLKS, Jeep invented the CAI. The Jeep was box stock, owner had died years ago and family finally got mom to move to a rest home and the ranch was sold.
Jeep used a oil bath air cleaner and attached to that was a HOSE that ran to the Headlight bucket, boys we found the CAI that actually works. So I converted by. removing my headlight trim ring and running a Jeep intake tube (take off) from the filter box into the back of the passenger side headlight bucket. I called it "Trash Air" because I used a round plastic trash can screwed to the back of the headlight support.
Results: SOLID +1-1.5 mpg
NO overheating...Trail rides became fun again: Me, my Rubicon, Supercharged and better mpg and ICE COLD AIR and I could idle all day and never overheat.
Some pics:
That’s some really interesting information. Unfortunately I’m not sure the 6 blade fan would help me. Whenever I slow down from highway speeds, everything cools down. I think my fan is operating properly, because even with a hot engine, it cools it down right away when I slow down. Plus the amount of air I have pushing through the grill at freeway speeds should keep the Jeep cold anyways.
It has to be a different aspect of the cooling system or perhaps even the oil pressure like some members are mentioning. Or perhaps my 4.0 hates every part that isn’t MOPAR. Lol Really stumped. The Jeep is a great drive around town vehicle right now but doesn’t want to go fast (65 MPH lol).
It did work for me, but it took the 3 things I mentioned to get Sonoran Desert cool after the SC was installed.
I doubt its Oil pressure.
Few questions: You have a new engine I think. What compression ratio are you running? THE OEM engine will run off pizz it about 8+/- : to 1. If you replaced the pistons with high compression, say 10:1 that is going to generate a lot heat.
Auto or stick? Auto will put out a LOT of heat, especially in the summertime. I know some guys out in Phoenix that were adding heavy duty trans radiators...
Can you run 87 Octane or do you need to run 89 or 91?
What temp is your thermostat on the engine??
I don't think oil pressure is the cause but it's a solid indicator the engine was not rebuilt correctly.
Wrong pistons is an interesting theory.
Sure would be interesting to tear the engine apart and get answers.
-Mac
JKP
TJ Addict
Well, we need to see the actual oil pressure numbers to know if it's even an issue. It could just be a bad sending unit or gauge.
A compression test could be done to determine if the numbers are within spec.
A compression test could be done to determine if the numbers are within spec.
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