I recently had the coolant system worked on due to a strong coolant smell while driving. I replaced the thermostat, housing, plastic manifold above thermostat and serpentine belt.
The smell did diminish but I could still smell it a bit. My mechanic said there was coolant burning off from the repair and it should go away.
Since then, I had a hose replaced on the ac system and it was at the rear of engine and traveled to the bottom front. They had to drop the suspension to get it swapped out. Now I seem to smell a strong coolant odor from the area where the hose meets the ac on rear of engine near windshield. I think I see coolant on a coupling where a hose clamp is right behind engine.
Any ideas??
Tis car will NOT get the best of me!!
Did I mention the check engine light came on within 8 hours of picking up from mechanics?

 

Make sure you're not losing any coolant. Check your coolant level. I'm thinking, maybe there is a loose hose or some parts weren't correctly sealed. In my case after fixing my leak I was losing a considerable amount through the plastic manifold connected to the thermostat. I had to apply some high temperature resistant silicon and sealers to stop the leak. I too was noticing a smell of coolant prior to that. It was a DIY job that took me about 2 hours.

 

A pressure test is probably advisable to see or hear the seepage with the engine off.

You should consider repalcing that part...it is not very expensive. I am just worried that if the adhesive failed the manifold can rupture and lose coolant very fast and overheat the engine without you even knowing. In the meantime, if you get a low coolant warning, pull over without delay.

 

Have the heater hoses checked. I had a very similar scenario and the couplings on the "octopus" of heater hoses buried behind supercharger were leaking slightly, where I had to add a few drops of antifreeze every few weeks but could smell antifreeze every time I drove the car.

 

+1 on WhiteXKR's pressure test. I will add this though: To me, the usual smell of both my '97 and my current 2001 smell(ed) like evaporating coolant when driving, especially when idling and right after I turn(ed) them off. I was never losing coolant as judged by looking in the reservoir though. Its impossible to understand the degree you smell this but do check the reservoir before starting each day and see if it is changing. If the level is maintaining itself your mechanic could be right (and truthful) that it is just residual spill from a repair or its "just the way your running engine smells".

 

Curious. Now would that heater hose connection be behind the engine, below the windscreen? Thats where the strongest smell is coming from and also the location of what looks like moisture on a pipe just after a hose and clamp.

As for thermostat area, everything has been replaced there, except the pump, and no smell really coming from that area. It's definitely coming from the back of the engine area where they just did the ac hose work.

 

Jaguar's plastic coolant reservoirs become fragile after a few years, and a well-known issue is that the reservoir's hose nozzles tend to hairline-crack and leak almost imperceptively. It is very common for techs (and DIY owners) to inadvertently crack these nozzles by bumping the reservoir when working in the engine bay. The S-Type appears to suffer even more frequently from this problem than the XK series does....

 

Considering that I did that repair during the holidays and my coolant level hasn't dropped at all. I think I did a pretty good job.

 

That's great, I have no doubt you did a good job.

The issue is that plastic under constant thermal cycling has a tendency to continue to deteriorate and the fissures that you sealed up will likely continue to expand over time.

 

Think we found the leak!! It wasn't the heater hose (octopus) it seems to be a plastic coupling a hose connects to. 10.00 part!!
Also had check engine light come on yesterday as well. Turned out to be three misfires. New plugs and no problem now. Hope that's that!! Unless a coil or two. Plugs were original and totally fouled.

 

Yeah, but it wasn't the plastic part itself what I applied the sealant to, I applied it to the metal part, where two parts connected.

 

Hi All,
Just took the Jag out from winter storage a week or so ago and noticed a strong smell of coolant burning once the engine warmed up. I could see a few dried drops on the manifold shield under the coolant header tank. I remove the tank a replaced all the standard hose clamps with worm gear clamps, I doubled up the clamps at both sides of each connection and the smell has gone. Now at traffic lights I don't get that sweet smell of burning coolant wafting through the air. Easy job, less than an hour from start to finish.

Thanks,
Karl

 

I HATE that smell!!! I'll spend any amount of money to get rid of it!! But I'll drive around in worn tires!!! Lol