2010 KK 2.8 CRD - no cabin heat! (but I have some clues)

JimKKcrd · **Joined:** Sat Nov 25, 2017 8:28 am **Posts:** 6

Hello. First and foremost, excellent forum!

New owner of a used 2010 2.8 CRD, coming from a '99 XJ (2.5CRD).
So far so good, but haven't really cut loose with it just yet.

After reading through the great info here, replaced air and fuel filters, cleaned the MAP sensor (wasn't easy to find!). I can't get the "hood" light (hood switch works) and "TPMS" light to go out (pressure is good), but not sweating those right now.

I'm writing about very little / almost no cabin heat. Hoping someone can help. Some info:
1. OBDII (bluetooth dongle) device, reports 78C / 172F coolant temp
2. the temp gage on the dash is a smidge to the left of high noon. sounds normal.
3. blend door seems to work. pulled the motor, it actuates on command, the door is not stuck
4. blower works fine, from off to full blast.
5. heater core hoses both get hot. Well not HOT HOT, I clocked them in at 50-55C (~130F). I couldn't find anything else under the hood hotter than that, so I think the coolant is all at the same temp (78C if the OBD is to be trusted.)

Not sure where to go next! Does the 2010 KK have a heater core valve? Didn't see anything in the lines immediately near the H.C.

Any help would be greatly appreciated. Thanks!

TURBO-DIESEL-FREAK · **Joined:** Sat Apr 17, 2010 3:29 pm **Posts:** 1167

JimKKcrd:

Exactly what CRD engine is in your 2010 KK... is it a V.M. Motori R428 engine, or a V.M. Motori A428?

If you are running 78 dergrees Celsius or 172 degrees Fahrenheit, (full operating temperature?), your engine is running too cool, and you are going to have long-term problems with your engine.

If 178 degrees is the true operating temperature of your engine, you are not only getting poor cabin heat... you are also not getting optimum power production, fuel economy, and will have a clogged out engine years down the road.

I suspect a thermostat problem.

JimKKcrd · **Joined:** Sat Nov 25, 2017 8:28 am **Posts:** 6

Jeff, good point. Not sure which engine is in there, will have to have a closer look.
I can tell you the coolant lines run behind and under the engine, against the firewall.
My thermostat must be somewhere under the battery / fuel filter / alternator somewhere.
aka, pain to get to

I'll to try to get this to a dealership for a quick scan, see what they have to say.

Thanks!

papaindigo · **Posted:** Sun Nov 26, 2017 7:49 am

Ignoring whether or not the coolant temp is running on the cool side that's irrelevant with respect to cabin heat as your coolant is getting hot if not hot enough. If both heater core lines are hot, 130F is reasonably hot, and if coolant is flowing thru both lines then you should feel some cabin heat at the heater vents.

Comments:
1. I have no clue if the KK has a heater coolant line on/off valve; the KJ does not. The only way to tell is to look at a KK manual if you can find one. If not look at the lines; if there is a valve it will be on the inflow to the heater core line and will be easy to spot.
2. assuming the KK "doors" are the same as the KJ "doors" you have a) doors that direct the flow of air to various vents and b) doors that direct flow thru or not thru the heater core but they use different motors. Are you sure you pulled the blend door motor? I'm not sure you can even get too it on the KJ.

My guess and that's all it is is that the blend door is not, in fact, moving. Either stuck, unlikely, or the motor you checked is the vent one. Alternatively notwithstanding both hoses getting hot the heater core is plugged. You can back flush by pulling both hoses and using a garden hose at LOW pressure sending water back thru the heater core.

Best I can do from a KJ perspective.

JimKKcrd · **Joined:** Sat Nov 25, 2017 8:28 am **Posts:** 6

Thanks papa. I'll have another look but I'm pretty sure I got the right motor/door. It's the one that moved when I moved the hot-cold selector. Access is pretty easy, it's right above the accelerator.

I'm slowly warming up to flushing the heater core. The only thing slowing me down is not knowing which hose is which (in/out). They disappear down below and around the engine, to follow them around I'd have to take apart 1/2 the engine bay (slight exaggeration, but not as easily identified as usual).

That, and the mess of course.

I suppose I can flush both ways to play it safe.

90 PSI should do it. :mrgreen:

WWDiesel · **Posted:** Sun Nov 26, 2017 3:36 pm

If your model has the belt driven viscous heater like our CRDs, the inlet hose comes off the back of it going to the heater core.

DO NOT put any pressure over ~16 psig on heater core!!!! :grim:

If you do, you will be replacing it. They are NOT designed for much pressure! :roll:

Flushing with a low pressure garden hose should be plenty sufficient while you have BOTH hoses disconnected to flush it out... :wink:

Be sure and flush in both directions, inlet and outlet.

JimKKcrd · **Joined:** Sat Nov 25, 2017 8:28 am **Posts:** 6

Flushing the heater core appears to have done the trick!

Wasn't too difficult once I got the coolant tank and hoses out of the way. Would've been a 30 minute job if I hadn't dropped a 10mm wrench down into the engine :oops:

Surprisingly, not very much "stuff" came out. Used a garden hose, flushed both directions, got... a tablespoon? of pinkish goop.

Once engine is up to temp, I'm getting much hotter air than before, though still not HOT hot.

I guess with ~80C coolant temps, it's probably about right. Would've expected the viscous damper to have gotten me up to temp faster but I had to drive a good 7-8 miles in 45* weather to really feel heat coming out of the dash.

Thinking back, I should've washed it out with some detergent. I bet the insides are still slimey.

I'm not much of an "additives" kind of guy, but anyone recommend anything I could dump into my coolant?
Or is that a no-no?

Anyway, thanks again!

WWDiesel · **Posted:** Tue Nov 28, 2017 10:47 am

No additives that I know of!
You may just need to go ahead and do a complete cooling system flush using a good chemical flush product designed to clean out the cooling system.
If the heater core was full of *gunk, then the radiator and / or engine probably has their share of it as well.

(*if someone put the wrong type of antifreeze in the cooling system, it may account as to why you are having problems? Other types of antifreeze don't mix with HOAT coolant and can cause some weird chemical reactions with each other making gunk!)

A good acid flush followed by a neutralizer will clean the system very well. Just be sure and bring the system to full operating temperature so the **thermostat gets wide open to allow full flow (flush) through the radiator.

Then do a good clear water flush, then drain everything good, and refill with HOAT or hybrid-OAT antifreeze coolant like Zerez G-05 or equivalent!
DO NOT us any other type coolant in this engine!!

(**since the thermostat cannot be taken out of the cooling circuit on this engine!)

:SOMBRERO:

2010 KK 2.8 CRD - no cabin heat! (but I have some clues)

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