my heat starts to blow cold at idle or anything under 1,500 rpms ive replaced the water pump and had the system flushed out and refilled the heat blows hot when I’m driving but as soon as the rpms drop below 1,500 it starts to cool off does anyone have a solution for this it’s driving me crazy and everything else in the system seems to be working as it should

 

when the rpms drop below 1,500-1,000 the heat starts to blow cool when I’m driving it’s hot as can be I’ve replaced the water pump and had the system flushed and everything else in the system seems to be working as it should except when the rpms drop and heat starts to blow cool has anyone else had this problem with their Xtype this is my first Jag so I’m learning I do have a little car knowledge Thanks

 

What car?

 

Your low on antifreeze. You may have to jack up the front end to "burp" it completely. Somehow you have to get all the trapped air out of the system.

Make sure all the leaks are fixed.

Continued use in this condition may do very expensive damage.

 

If the car is x300 or later it may have an auxiliary water pump, these fail and normally require new brushes.
It really does pay to note which car you have.

 

Change your thermostat.

 

I didn’t think it was that because when they fail it’s usually in the open position so my heat would blow hot all the time correct? But I did buy a new 1 so looks like im putting it in Thanks

 

sorry just realized it’s a 2002 xtype it’s not low on coolant I just had the system flushed and refilled I can’t find any leaks and I replaced the water pump the car runs at normal temperature never gets above about 208 degrees where the fan kicks on I seem to hav good circulation the hoses are hot and pressurized when at temperature I replaced the coolant tank next I’m going to replace the thermostat even tho I don’t think it’s bad I’m just puzzled and trying to figure it out before I take it to the dealership…Thanks for input

 

Welcome to the forum Bostonchad,

I've moved your identical question from General Tech Help to X-Type forum and merged the threads together. Do NOT multiple post the same question across the forums.

Please follow this link New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum to the New Member Area - Intro a MUST forum and post some information about yourself and your vehicle for all members to see. In return you'll get a proper welcome and some useful advice about posting to the forum.

Graham

 

The x-type cooling system is a High Velocity / Low Volume cooling system. I would be willing to gamble that your problem did not occur until after a flush and refill. You have air trapped in the heater core and the system is low on coolant.
There is a complicated burping procedure in the tech manual but I have always used a simpler method. First manually set the climate control to HIGH. Then take it out for a spirited drive. Once home check and top off the coolant. You may have to make 2 or 3 spirited trips. (but hey that's the fun part of a Jag)

Once you are sure all of the air is out of the system you can set your climate control to your normal setting and motor on happily snug and comfortable.

 

The fact that it just had a flush and fill does not mean it was 'burped' properly. You could very well have air trapped in the system.

 

Is it possible that im sucking air into the system from somewhere? They did say I had air in the system when it was flushed plus the previous owner had switched coolant to the regular green stuff at some point so I had it switched back to the Dex (orange) coolant which is recommended by Jag. Since it is winter time here in Michigan this is going to drive me nuts until I get it figured out!

 

The system is self venting and will not draw air in under normal operation. You noted you switched from green to orange. Do you know if the person doing the flush filled and drained the system with fresh water with the heater going.

Have you tried the recommendation of burping while driving? If that wasn't successful the here is a link to follow. Scroll down to the bottom of the page and you can download the tech manual and follow the burping procedure in the tech manual.https://www.jaguarforums.com/forum/x...essories-5915/

If you had green coolant remaining in the heater and have now introduced orange then it is possible that the heater core is partially blocked with the gelatin that mixing the 2 produces. If that is the case you will need to remove the inlet and outlet hoses from the heater and back flush it.

Once refilled you will still be back to burping.

 

Delete duplicate posting

 

You "could" also have a blown head gasket letting antifreeze into a cylinder. Sometimes they start so slow your only indication is an antifreeze loss. I had that with a 4 cyl. once. Kept losing antifreeze and couldn't find a leak. I pumped it up and it held pressure for 24 hours. I pulled the plugs and the last one I pulled had green in the cylinder. Found my leak.

 

I had the flush done at a ford dealership and I explained my problem to them before they did it so I would hope that they did the flush correctly I haven’t tryed the burping while driving method I’m going to check that out and as far as a head gasket I’m praying that’s not the problem because I don’t have any other signs of that thank guys

 

You can play with it as long as you want but if you can't find the problem soon.you would be better off paying $20, maybe $30 now, for the pump up kit and put some pressure on the radiator and see if it will hold pressure. The pump has a built in gauge to show you how much pressure you have on it. Just put about 12 pounds on it and see how long it holds. If you lose it fast then look the motor over good to see which hose is leaking. If it holds a long time pull the plugs and look in the cylinders, I've never had a car that didn't lose a head gasket unless it had a cast iron block and heads. Aluminum seems to always blow out gaskets and usually warp and need a shave. If you wait too long it'll warp beyond shaving and that means a new head. The aluminum intake on my '86 warped too much and had to be replaced. Luckily that engine was everywhere in the junk yards and I got one cheap. Your local machine shop can check the head for flatness and shave it flat if needed. Or tell you it's beyond salvaging.

 

I see you replace water pump and flushed the coolant,but you didn't replace the thermostat; The thermostat can be stuck in two way: If it stuck closed, then you get engine over heat. If it stuck open, in the idle coolant flowed through engine all the time so it not get hot enough, tn the cold weather the blower draw the cold air in make the heater core colder that's why you got cold air. Check the thermostat, some thing stuck in prevent it to closed. To check the thermostat is function or not: Take it out and if it's open see if any thing stuck in the diaphragm, if it's closed put in a small pot with water, cook it on the stove, observe to see if it open when water is boiled, take it out and watch as it's cool down if it closed, thermostat still working.

 

I do have a brand new thermostat I’m just going to put it in and check on a pressure tester to test the system.Im going to keep at it till I figure it out I appreciate the input fellas!.

 

I'm hoping the thermostat and more burping does it. Don't mean to scare you just help in case it does turn out to be the worst case scenario. If you do a head job though, be careful which side is up on the new gasket.

I took a 6 cyl in once for an exhaust leak. They gave it to a new guy as his first project. He found an exhaust stud broken on both heads. They sent them out to a machine shop. When I got it back, I drove it to work that night and noticed the temp gauge was running a little higher than normal. I popped the hood at work and the bottle was empty. I wondered where my antifreeze went so I pulled the dipstick and found chocolate milk all over it. Found my antifreeze, it's in my engine oil. I had it towed back to the shop and they tried again. They magnafluxed the heads to make sure no damage was done and put the new gaskets on right side up. Didn't charge me a penny for it. I did pay for the wrecker though. Good luck with it