Topic: ZJ - No heat! (Read 6662 times)

XJ Fan · « **on:** March 19, 2015, 08:23:37 AM »

Driving the ZJ yesterday and noticed no heat coming from heater vents. I tried with and without A/C, varied temp, fan speed and vents, but nothing but cold air.

Is this the dreaded blender unit at fault? if so, how can I test and make sure? She is losing coolant as well, so could there be an air pocket in the rad/heat exchange?

Please help!

gazjeep · « **Reply #1 on:** March 19, 2015, 11:12:41 AM »

Could be what you have suggested but where is it loosing coolant from ?

Water pump is always a favorite & dont discount a dicky thermostat. What is the temperature gauge showing ?

XJ Fan · « **Reply #2 on:** March 19, 2015, 11:19:54 AM »

I don't know where it is losing coolant from, although it is somewhere at the front of the engine - I suspect the rad or similar.
The temp gauge is reading normal (about midway), and was constant once up to temp.

I'm taking her to an LPG servicing place tomorrow for them to give the LPG system a once over (not sure if there are any serviceable items?), so will ask them to look for leaks as well.

bgbazz · « **Reply #3 on:** March 19, 2015, 02:44:35 PM »

As Gaz said, it could be any of the above, but once you have the engine up to temp and switch heater control to highest temp...grab hold of both heater hoses under to bonnet (feeding the matrix) and see if they are both fairly warm, almost hot. That will help isolate the problem area.

XJ Fan · « **Reply #4 on:** March 19, 2015, 07:26:19 PM »

Thanks for the help. Got any pictures of the hoses that feed the matrix, to help me find them?

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Brynjaminjones · « **Reply #5 on:** March 19, 2015, 07:42:40 PM »

If it's like an XJ, they run along the left side (looking from the front) of the valve cover.

bgbazz · « **Reply #6 on:** March 19, 2015, 08:30:52 PM »

If both hoses are heated...problem is in the matrix/heater control area...if one hot and one cold...same area. If both cold, problem is around the water pump/thermostat area.

The temp control is just a fancy tap...it controls the flow of hot water/coolant and I've seen them seize open or shut, many times.

This simple and free check will isolate your problem area.

big g · « **Reply #7 on:** March 19, 2015, 09:04:25 PM »

Didn't think zjs had blend doors

My old XJ was piss poor due to the matrix being full of crud.
Back flushed it and after was reeeed hot.

bgbazz · « **Reply #8 on:** March 19, 2015, 09:26:06 PM »

Quote from: big g on March 19, 2015, 09:04:25 PM

Didn't think zjs had blend doors

My old XJ was piss poor due to the matrix being full of crud.
Back flushed it and after was reeeed hot.

Being full of crud is the most common problem, after a faulty tap...I remember backflushing a Landcruiser matrix and having a very long turd appearing from the outlet pipe...took two or three tries to get the water to run clear and fast, but it also produced super hot air afterwards.

bigjeepzj · « **Reply #9 on:** March 19, 2015, 09:42:53 PM »

The bleed tap on the drivers side bottom of rad can leak.
the first thing normally to stop working is the heating.
fix leak flush system, refill and burp it leave rad cap of and run engine till hot it gets the air out

see what happens

bgbazz · « **Reply #10 on:** March 19, 2015, 09:53:35 PM »

That makes sense...in that case, the hoses would be barely warm, maybe even cold.

XJ Fan · « **Reply #11 on:** March 19, 2015, 10:22:38 PM »

Thanks for all the help guys, I know what I'm doing on Saturday!

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bgbazz · « **Reply #12 on:** March 20, 2015, 11:28:28 AM »

Good luck with that...hope it turns out to be a simple fix.

Bubba · « **Reply #13 on:** March 20, 2015, 01:31:23 PM »

its got a burp stuck in the heater matrix i reckon

XJ Fan · « **Reply #14 on:** March 20, 2015, 05:16:18 PM »

Ah, water pump looks fecked - the fan wobbles like mad with the engine running. Hopefully that's the extent of any issues.

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bgbazz · « **Reply #15 on:** March 20, 2015, 05:20:09 PM »

What about the hose temps? And is there any movement of the fan shaft, with the engine switched off...can you wriggle it?

XJ Fan · « **Reply #16 on:** March 21, 2015, 08:37:23 AM »

One hose is warm,the other not. The system isn't pressurising, and I can move the fan when the engine is not running.

bgbazz · « **Reply #17 on:** March 21, 2015, 09:03:25 AM »

Well, the pump needs some close attention for a start, but the matrix is where the non heating problem lies, in my opinion.
I would get the pump sorted first and while thats going on, try a full flush of the heating system using medium pressure and a garden hose...you might be surprised at what comes out!

My money is on a blockage in the matrix or the tap seized in the closed position.

bigjeepzj · « **Reply #18 on:** March 21, 2015, 10:41:08 AM »

The fan is on a viscose coupler so will turn when engine not running.
it's a blockage or burp

bgbazz · « **Reply #19 on:** March 21, 2015, 10:59:46 AM »

Quote from: bigjeepzj on March 21, 2015, 10:41:08 AM

The fan is on a viscose coupler so will turn when engine not running.
it's a blockage or burp

Sorry, I should have been clearer...I didn't mean turning, but unusual sideways or up and down movement in the whole thing.

XJ Fan · « **Reply #20 on:** March 21, 2015, 05:43:25 PM »

Yes BG, the fan rocks on its' axis both when the engine is running, and not. The water pump is my prime focus and should be sorted next week; there should also be a full heating system flush and new coolant. With that working, then I can see if the heater problem is sorted or not. I'm taking it to a garage, as I don't have the experience to do something like that myself.

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bgbazz · « **Reply #21 on:** March 21, 2015, 06:27:22 PM »

That's the way to go...get the pump sorted, have a decent flush done...fingers crossed for a good result!

Wish I lived closer....I thrive on problems and hiccups like this this and would have happily sorted it for you.

Make sure the garage knows about the posssible heater blockage problem and the need for a proper flush.

XJ Fan · « **Reply #22 on:** March 23, 2015, 12:34:56 PM »

Appreciate the offer BG, wish there was someone closer to me as well!

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XJ Fan · « **Reply #23 on:** April 03, 2015, 11:44:59 AM »

OK, new water pump and coolant, and got heat again! I put it down to the knackered old pump - apparently it was about to implode.

bgbazz · « **Reply #24 on:** April 03, 2015, 12:48:21 PM »

Author Topic: ZJ - No heat! (Read 6662 times)

big g