I am noticing a smell when the heat is on. The smell does not occur when the air conditioning it is on. I cannot tell if it is a coolant smell or an exhaust smell or a combination of both.

If anyone has some advice on where to start to diagnose the problem I would appreciate it. Thanks.

 

When did you last change the filter? Is the engine losing any coolant? There is only one set of flappers that direct hot/cold air, the rest of the ducting is the same.

 

I have a very small coolant leak somewhere in the front of the engine. About a thimble full after sitting for a few weeks. Nothing substantial that I have noticed at the moment. Does coolant always run through the heater core or does it only turn on when the heater is on? I suspect I would see a leak maybe if it was large enough but not sure.

 

The core always flows hot coolant. Sometimes the hole can be really small and not really be an issue unless the coolant is hot, in which case it escapes pretty much as steam.

 

Interesting. I have not changed the filter. I'm really hoping it is not a leaking core. Looks like a big job to change. Could it be sucking in exhaust gas from somewhere? I'm just trying to work through all of the possibilities. When the air conditioning is on, there is no smell or fumes. When the heater is on I need to have the window cracked or sun roof open. With the hood open I do not see any exhaust fumes from either exhaust manifold or collector. I have also ruled out a rodent. It is not that type of smell. More of a chemically smell that I can tell is not setting well with my human body.

 

The core job can be pretty easy with a couple shortcuts. The only place exhaust can get in would be from the intake duct below the windshield. Or if you have an exhaust leak it can creep almost anywhere into the cabin other ways.

 

Alright thanks. I'll try to smell the coolant tank before starting the truck tomorrow to see if I can identify it better when it is running. I suspect an exhaust leak would not be only happening when the heat is running.

On the shortcuts for replacing the heater core, is there any videos or references on how to do it the easy way? I just replaced the electric parking brake and it was a pain.

 

I would link, but the link has images on this forum and they are not loading for some reason. But somewhere recent in the "What did you do to you LR3 today" thread normally shows pics of how the dash was cut to slide the core out.

 

To OP, this is the post DakotaTravler meant, https://landroverforums.com/forum/lr...53/#post901217

I couldn’t find anyone who had documented it with pictures so as I had to bite the bullet and get it done decided to contribute something to the discovery 3 body of knowledge. Most posts said “oh it is no big deal”, “was easy”, etc. but seeing one done helps usually one’s own repair jobs…

Stuff I didn’t bother documenting in the post were:

• remove extra fluid from pipes going to the heater core, there was almost no spill when I took off the pipes in the cabin
• how to remove the lower glove box, it’s not tricky you just need a proper tool, YouTube helps here
• Reused existing pipes, discarded the new ones that came with the new core
• how to bleed the cooling system once you’re done

It’s below freezing now here and I’m very happy to report that I’m getting warm on the driver’s side once again 😂

FWIW, I used a Nissens heater core.

 

Wow. Thank you for the post. You definitely make the job look much more manageable with a few smart cuts. Thank you for the link, I really appreciate it. I scrolled a little and did not find it at first.