Engine not reaching proper temp/no heat??

Alrighty so Im done messing with it today, I checked everything that everyone has suggested and I have come to the conclusion that the gauge must not be reading the proper temp. I drove it for about 20 minutes around town and at highway speeds, came back home popped the hood and put my hand on the thermostat housing and had to take it off after about a second because it was HOT!!! I also felt the upper radiator hose and it was warm, felt the heater core hoses closer to the front of the motor and they were warm, I then moved back right next to the firewall and felt the heater core hoses and if I remember correctly the bottom one felt a little warmer so I think the heater core will need flushing. Its to cold for me to flush it at home so ill probably take it to the shop again on Monday and have them do it, I might also pick up an aftermarket temp gauge if I feel like putting it in. Ill update from there. Thanks again for the help guys
 
If the heater core is clogged up then there's probably air trapped in those lines and messing with the coolant sensor. The heater hoses should get as hot as the thermostat housing, so based on the tests you've done so far just flush out the heater core with garden hose (front and back) and test again.

What year vehicle is this?
 
Its an 87

I would say the hoses are pretty warm I wouldnt consider them to be as warm as the thermostat housing since that is metal, but I would say they are warmer than what my gauge is telling me.
 
Tynamite 87 said:
I also wrapped the overflow tank threads with a lot of teflon and that seems to have stopped the air leak issue.
Click to expand...

One of the major malfunctions with the closed radiator system on the XJ is the pressure bottle on the firewall.

You need to make sure that the pressure bottle, when cold, is no more than 1/3 full. Open systems use the recovery bottle to hold expanded coolant, and the vacuum created when the coolant in the radiator cools sucks the coolant back from the recovery bottle. In the closed system all coolant is retained in the system, so there has to be room for expansion or things will "blow".

The pressure bottles (OEM and aftermarket copies) tend to be impacted by the hood against the cap, and this contributes to cracking in the pressure bottle and premature failure. Also, as you have noted, the caps don't seal very well and this contributes to overheating as pressure is required to raise the boiling point of the coolant. Use of a Volvo pressure bottle cap will help with a couple of these points. The cap seals better with the OEM/Aftermarket bottles, the caps have a higher pressure rating so the boiling point of the coolant is raised, and the caps have a much lower profile so the hood impacting against the cap/bottle is eliminated. The Stant Volvo 740 2.3L style cap for $8.95, #10244 is the upgrade. Another alternative, as mentioned earlier, is to put a worm clamp around the cap to seal it better. Wrapping the threads on the bottle won't last long, it has been tried and it fails. However, using the worm clamp does nothing for the problem of the hood, and that will eventually cost you the bottle.


You can try and locate an alternative pressure bottle in the salvage yards. Volvo and other Chryco vehicles are good places to look. Take a few measurements and go hunting, just make sure and get one that is slightly lower in height for overall clearance.
 
It's kind of hard to flush out the core in cold winter weather with water. Maybe a hose connected to a hot water heater. And then you have to get antifreeze in and mixed before it all freezes up.

If flushing doesn't work, you may have to accept the possibility (as some others have reported) of the core just being too gummed up to transfer the heat out of the coolant. I've seen this even happen on cores less than 2 years old when the wrong types of antifreeze were used. (We had to cut the cores apart to analyze them for warranty issues.)
 
Thanks for the info guys ill probably pick up one of those volvo caps and ill just let the shop deal with the flushing since i dont want to have water freeze up on me.
 
magimerlin said:
As far as the heat is concerned... try flushing the heater core out, it may have a slight blockage. Make sure that your blend door is moving when you tell it you want hot air. An 87 should be cable operated and is visible by looking under the passenger side of the dash. You should see a lever with a metal rod attached to it that goes into a sleeve up to the heater controls. Also check your heater valve to make sure it is working, it is controlled by vacuum and if there is a leak, well you guessed it, it will not work and will not let hot water into the heater core..
Click to expand...

techno1154 said:
However, the control valve for the hot water in the engine compartment is vacumn operated.
Click to expand...

If you actually read my post I did mention that. I put it in bold for ya....
 
I'm going through the same thing right now. At first I thought I needed to replace my heater core but now I believe my engine is not reaching the correct temperature. I have a short commute to work ~10 min and I don't think that is allowing enough time for the engine to warm up. On days I drive all over time or allow my jeep to idle for around 20-30 min before I leave I will have hot heat. I ordered a temp gauge and I'm going to install it this week to see if my temp is actually getting to the correct temperature.
 
joe_peters said:
One of the major malfunctions with the closed radiator system on the XJ is the pressure bottle on the firewall.

You need to make sure that the pressure bottle, when cold, is no more than 1/3 full. Open systems use the recovery bottle to hold expanded coolant, and the vacuum created when the coolant in the radiator cools sucks the coolant back from the recovery bottle. In the closed system all coolant is retained in the system, so there has to be room for expansion or things will "blow".

The pressure bottles (OEM and aftermarket copies) tend to be impacted by the hood against the cap, and this contributes to cracking in the pressure bottle and premature failure. Also, as you have noted, the caps don't seal very well and this contributes to overheating as pressure is required to raise the boiling point of the coolant. Use of a Volvo pressure bottle cap will help with a couple of these points. The cap seals better with the OEM/Aftermarket bottles, the caps have a higher pressure rating so the boiling point of the coolant is raised, and the caps have a much lower profile so the hood impacting against the cap/bottle is eliminated. The Stant Volvo 740 2.3L style cap for $8.95, #10244 is the upgrade. Another alternative, as mentioned earlier, is to put a worm clamp around the cap to seal it better. Wrapping the threads on the bottle won't last long, it has been tried and it fails. However, using the worm clamp does nothing for the problem of the hood, and that will eventually cost you the bottle.


You can try and locate an alternative pressure bottle in the salvage yards. Volvo and other Chryco vehicles are good places to look. Take a few measurements and go hunting, just make sure and get one that is slightly lower in height for overall clearance.
Click to expand...

My bottle cracked 2 months ago so I had purchased a new one. Supposedly the cap already has a valve in it allowing pressure to be released if the coolant expands to much. This is of course what I read about the OEM cap. Is this not the case?
 
MudfrogK5 said:
My bottle cracked 2 months ago so I had purchased a new one. Supposedly the cap already has a valve in it allowing pressure to be released if the coolant expands to much. This is of course what I read about the OEM cap. Is this not the case?
Click to expand...

The caps DO have a pressure relief in them. That said, my experience with the caps is that the contact of the threads on the bottle with the threads in the cap is insufficient. This problem is very pronounced on the aftermarket bottles, and seems to degrade rapidly so that after a very short time when you try and tighten the cap--after checking/topping off the coolant, or you notice some coolant pooled on top of the bottle, and you try and tighten down the cap it will "strip" and won't tighten down. Quick fix is run the cap all the way down but don't try and tighten it fully. Put a worm clamp over the cap and cinch it down to compress the cap around the bottle neck.

OEM dealer caps seem to work longer with the aftermarket bottles--the last aftermarket bottle I purchased the cap that came with it wouldn't stay on from the git go.

Ecomike has posted numerous, detailed threads on his trials and tribulations with the closed system. One thing he discovered is that there is a large variance in the height of various caps, and that contributes to the problem of hood impact.

Some posters have lowered the pressure bottle shelf to eliminate contact with the hood.
 
joe_peters said:
The caps DO have a pressure relief in them. That said, my experience with the caps is that the contact of the threads on the bottle with the threads in the cap is insufficient. This problem is very pronounced on the aftermarket bottles, and seems to degrade rapidly so that after a very short time when you try and tighten the cap--after checking/topping off the coolant, or you notice some coolant pooled on top of the bottle, and you try and tighten down the cap it will "strip" and won't tighten down. Quick fix is run the cap all the way down but don't try and tighten it fully. Put a worm clamp over the cap and cinch it down to compress the cap around the bottle neck.

OEM dealer caps seem to work longer with the aftermarket bottles--the last aftermarket bottle I purchased the cap that came with it wouldn't stay on from the git go.

Ecomike has posted numerous, detailed threads on his trials and tribulations with the closed system. One thing he discovered is that there is a large variance in the height of various caps, and that contributes to the problem of hood impact.

Some posters have lowered the pressure bottle shelf to eliminate contact with the hood.
Click to expand...


Ok, well for $8 for a cap that works properly I guess that's a good investment. I might look into the Volvo cap.
 
Alright jeep is at shop right now I left it over night since I have no time because of school etc... but anyways I called the shop and he is working on flushing it right now he said right when he started to flush it a whole crap ton of rust and junk came flowing out and he said he's pretty sure it will work now. When I dropped it off I talked to the owner of the shop and asked him if they used a digital thermometer gun on it at all and he said yea and that it was at the proper temp so my gauge must be bad. I'll update in a bit when I go pick it up.
 
Awesome! Gauge reading the right thing now as well, or not yet?
 
You must log in or register to reply here.

Similar threads

S
Renix coolant temp sensors
Replies
4
Views
132
phydeaux33
phydeaux33
my2monkeys
aw4 running temps?
Replies
2
Views
87
Ol Blue
Ol Blue
S
Overheating final boss
Replies
19
Views
551
StimitheJoop
S
Z.m4v
Possible faulty temp sensor?
Replies
10
Views
594
clean96XJ
C
C
Renix Engine Coolant System Updates
Replies
5
Views
247
Saudade
Saudade
Back
Top