No heat, intermittent Heat <Problem Solved>

flman · **Posted:** Sun Oct 27, 2013 3:08 pm

I have a problem with my Sport. Now that it is cold out, you will have plenty of heat pulling a grade, and hardly any while coasting or waiting at a red light. Temp gauge varies from 1/2 way in the second quarter to near the top, it seems the hose to the rad is hot, I am thinking tstat again? BTW what temp is every one using for the inline tstat?

Thanks Bob

papaindigo · **Posted:** Sun Oct 27, 2013 5:10 pm

If your thermostat (OEM or inline) is functioning properly and all other cooling system components are ok (radiator not clogged, fans working ok, water pump pumping, heater core not clogged, coolant temp probe ok, etc) then your temperature gauge should sit essentially rock solid just a slight bit left of dead vertical. If it's below there or drops below there at say every stop light then you probably have a bad tstat The OEM one typically fails open or opening too early hence the coolant never fully warms up although it might on a hot day with AC or pulling a grade. If the temp gauge goes well up from dead vertical then I'd wonder why as that could be signs of a cooling system problem unless there is an obvious external cause like pulling a steep grade with a heavy trailer in really hot weather. Note we took stoutdog's 06 with Kap's modified OEM tstat out of Tempe south thru the valley past Tucson and on out of the valley to the east with probably 400lbs of passengers plus 4-500lbs of stuff in the car with a kayak on top pulling a fully loaded UHaul 5X8 trailer weighing ca. 2,000 lbs in 110+F ambient temps and the gauge never twitched above normal.

Regardless of the tstat your heater core water temp should be at least ca. 145F if the viscous heater is running properly. There is no "valve" in the heater core lines (heat on/off/level is controlled by the blend doors) so both lines running to/from the heater core should always be hot once the engine has been run a bit; if one is not you likely have a plugged heater core which is not uncommon if coolant other than HOAT has ever been used. You can backflush the heater core if need be by unhooking both lines on top of the engine, hooking a garden hose to the outflow line; and gently opening the garden hose flow.

Most posts on the in line that I've seen say 190-195F which is higher than the OEM but GDE says that's desirable.

flman · **Posted:** Sun Oct 27, 2013 5:38 pm

Actually it is not my vehicle, it is the wife's, we took it out tonight and the temp got real cold pulling a grade, then it warmed up coasting down hill, really erratic. The temp gauge changed about 2 notches cooler, I wonder if the stat is weak and the pump is pushing it open? I revved it in the driveway and the heat got super hot, I guess I will try the tstat and see what happens?

geordi · **Posted:** Sun Oct 27, 2013 6:13 pm

It could be a combination of a weak thermostat, but it could also be the water pump. Sounds like you are only getting heat when the engine is revving above idle, yes?

That could be an indication of a restriction, possibly just in the heater core itself, which is why the hose to the radiator feels hot. It could also be the water pump is not moving enough coolant, which is why I mentioned that. The CRD really has an oversized amount of cooling capacity for most operating conditions, so the loss of a thermostat just never allows the coolant to warm up. The easiest thing to try first (and cheapest) is the in-hose thermostat. If that solves the problem and the temp gauge stops wandering around as you are driving (this is unusual behavior)... Then you have found the problem. If that (instead) causes the temps to rise at all above the centerline... Then suspect the water pump. If nothing changes with the in-hose in place, you will need to pull off the hose to the heater core and flush the system - there have been several members who have reported a "sludge" build up in their heater cores. Reasons for this are still somewhat spotty.

dirtmover · **Posted:** Mon Oct 28, 2013 8:07 am

papaindigo wrote:

If your thermostat (OEM or inline) is functioning properly and all other cooling system components are ok (radiator not clogged, fans working ok, water pump pumping, heater core not clogged, coolant temp probe ok, etc) then your temperature gauge should sit essentially rock solid just a slight bit left of dead vertical. If it's below there or drops below there at say every stop light then you probably have a bad tstat

Based on the assumption that my original stat and it's replacement I put in a couple of years ago started off functioning correctly then this temperature wandering based on loading is normal when ambient temperature falls a bit below zero otherwise, as you point out, it should be rock solid. When you get down into the -20's °C this wandering can be quite dramatic i.e. a couple of ticks in less than 30 seconds.

Of course, I'm open to the idea that my vehicle is not normal and has had a problem from new but I've seen no other side effects of this.

pwrwagn · **Joined:** Mon Jul 22, 2013 2:40 am **Posts:** 192

It's not low on water, is it?

flman · **Posted:** Mon Oct 28, 2013 6:53 pm

Well I put in a 180 inline tstat, that is keeping the needle close to straight up, I flushed out the core, was clean with no resistance, some times I have excellent heat and sometimes stone cold, the inlet line hot, outlet line almost cold. Is that the EGR cooler return that goes into the Y fitting with the heater core return? FSM is pointing towards water pump if one line is hot and the other is cold.

Guess I should have changed the pump 12k miles ago when I was doing the timeing belt? :banghead:

geordi · **Posted:** Mon Oct 28, 2013 8:56 pm

Seems like that might be the problem. Unfortunately, you will want to do this sooner rather than later - Any problems in actually making the water FLOW mean that your temp gauge (which reads only from the probe in the thermostat housing) is very likely not giving you an accurate picture of water temperatures in the head itself.

If the water isn't getting out to the radiator in sufficient volume, the head temperatures could easily get to severe levels. Hopefully there is enough flow to prevent this... But it is hard to be certain. At least the temperatures outside are dropping, and hopefully this has been a recent development rather than brewing for some time.

A Graf water pump from IDparts and the belt are unfortunately in your future.

TJ2 · **Posted:** Mon Oct 28, 2013 11:43 pm

flman wrote:

Actually it is not my vehicle, it is the wife's, we took it out tonight and the temp got real cold pulling a grade, then it warmed up coasting down hill, really erratic. The temp gauge changed about 2 notches cooler, I wonder if the stat is weak and the pump is pushing it open? I revved it in the driveway and the heat got super hot, I guess I will try the tstat and see what happens?

This is exactly opposite of my experience climbing and descending a mountain pass. It keeps heat on level or climbing, and loses heat when descending any time the ambient air temp is below about 30F. All my heat/cool components are functioning as engineered.

FWIW, I'm tired of the OEM short lived t-stat. I've got a Stant 195F that will go in next time.

flman · **Posted:** Tue Oct 29, 2013 6:41 am

geordi wrote:

A Graf water pump from IDparts and the belt are unfortunately in your future.

Your a bad fortune teller :mrgreen:

, but I went ahead and ordered the pump, thanks for the input.

geordi · **Posted:** Tue Oct 29, 2013 12:37 pm

Hey, meester paid for fortunes to be told accurately... If meester wanted only good fortunes to be told, that was higher prices on the leest. Thanks you anyway for moneys, satisfactions with fortune is not always guaranteed to meester.

:-)r

Also.. That would have been "you're" in your usage. "Your" is possessive, "you're" is short form of "you are" which is indicative rather than possessive.

flman · **Posted:** Tue Oct 29, 2013 3:55 pm

geordi wrote:

Hey, meester paid for fortunes to be told accurately... If meester wanted only good fortunes to be told, that was higher prices on the leest. Thanks you anyway for moneys, satisfactions with fortune is not always guaranteed to meester.

:-)r

Also.. That would have been "you're" in your usage. "Your" is possessive, "you're" is short form of "you are" which is indicative rather than possessive.

I guess I meant to say, "You gave me a bad fortune."

geordi · **Posted:** Tue Oct 29, 2013 7:31 pm

Hey, I take no responsibility for that - Blame Chrysler for the bad luck, this was their design requirement.

flman · **Posted:** Wed Nov 06, 2013 8:11 pm

So I got it torn down today, but it does not look like the problem is the pump, I was not able to make the impeller slip with the drive pulley in a vice. I put it back together only up to the timing belt, and a quick test start with no fluid. My next thought is something is floating around in the block impeding the tstat outlet, and causing no heat considering the hose to the heater core comes off there, (correct me if I am wrong)

I was thinking of putting it 90% together, pulling the tstat, and forcing water through the engine, via the radiator return and see if any thing comes out.

Considering, no heat at high speeds (high pump pressure) vs low speeds (less water flow)?

I wish I could find a plumbing diagram for this engine? None in the FSM.

flman · **Posted:** Thu Dec 12, 2013 5:46 pm

So an update, since the pump job, I have replaced the tstat, and the engine is warming up to and staying at one tick before straight up, Still no heat.

Replaced the heater core, cut open the old one and found no blockage, Still no heat.

I verified all my hose connections were the same with my other CRD, Still No Heat.

I filled the system, pumped pressure and loosen any upper hose clamps to bleed off any air, Still no Heat!

I am starting to think I have a head gasket problem, as the system always has pressure in it, cold, or hot.

The harder you drive it, the colder it gets.

So, do I tear into it and pull the head? What is the most it would cost if the head is warped?

I considering getting rid of the CRD, but what in the world could replace it, other then another CRD?

BTW, I learned a good trick to drain the coolant, as draining the Rad sucks on these, pull out the bleeder and stuff a hose in there, apply pressure to the reservoir, and let the siphon begin. No more trying to turn that confounded drain valve.

jkbkwarner · **Posted:** Fri Dec 13, 2013 1:16 pm

flman wrote:

BTW, I learned a good trick to drain the coolant, as draining the Rad sucks on these, pull out the bleeder and stuff a hose in there, apply pressure to the reservoir, and let the siphon begin. No more trying to turn that confounded drain valve.

Couple of questions, where is the bleeder you're referring to and how could I apply pressure to the reservoir? I was looking to change my tstat last weekend and couldn't bring myself to cut the 10mm allen wrench I had using Squeeto's instructions (have since bought a cheap 10mm allen wrench).

flman · **Posted:** Fri Dec 13, 2013 5:08 pm

jkbkwarner wrote:

flman wrote:

BTW, I learned a good trick to drain the coolant, as draining the Rad sucks on these, pull out the bleeder and stuff a hose in there, apply pressure to the reservoir, and let the siphon begin. No more trying to turn that confounded drain valve.

Couple of questions, where is the bleeder you're referring to and how could I apply pressure to the reservoir? I was looking to change my tstat last weekend and couldn't bring myself to cut the 10mm allen wrench I had using Squeeto's instructions (have since bought a cheap 10mm allen wrench).

It is on the left side of the rad when you are standing in front of the vehicle with the hood open right above the drain plug. I use a cooling system test pump, but you could probably use the exhaust of a vacuum or a little compressed air. I hate pulling that plug, there is no neat way to do it, and it is time consuming.

flman · **Posted:** Fri Dec 13, 2013 5:12 pm

flman · **Posted:** Sat Dec 14, 2013 6:22 am

I got a few PM email reply's from a couple of the members hear. I am thinking a blown head gasket is causing aeration of the cooling system, and hydronic heat does not circulate with excess air.

Here is a video of my Rad cap being removed on a cold engine, my other CRD does not do this, does any one else have these symptoms on cold cap removal?

http://www.youtube.com/watch?v=4Go4FC0riQs&feature=youtu.be

racertracer · **Posted:** Sat Dec 14, 2013 2:45 pm

flman wrote:

I got a few PM email reply's from a couple of the members hear. I am thinking a blown head gasket is causing aeration of the cooling system, and hydronic heat does not circulate with excess air.

Here is a video of my Rad cap being removed on a cold engine, my other CRD does not do this, does any one else have these symptoms on cold cap removal?

http://www.youtube.com/watch?v=4Go4FC0riQs&feature=youtu.be

It sure looks like it.

But to be sure, test it by using a head gasket leak detector form NAPA.

No heat, intermittent Heat <Problem Solved>

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