2003 S-type 8 cylinder.

I just replaced the radiator fluid reservoir which was leaking at the little hose connection on top. So I thought all was good until I noticed I was still losing fluid everyday somewhere else. So while the car was running I watched to try and find it. There was no leaks anywhere up front by the reservoir.

Then I saw it dripping way back by the front of the transmission. I thought why would radiator fluid be back there? So I crawled under the car and all I could see is the fluid was coming down some pipe right behind the back of the engine in the space between back of engine and firewall. I can't get a view to see where it's originating from. It seems to only drip when the A/C is turned on.

I'm hoping maybe this is common and someone can tell me what's going on. THX

 

Just to let you know you have a heater core which is located in your dash which looks like a little radiator and thats what your air flows through to create the heat in the winter time. There are 2 lines that run up to that heater core that bring radiator coolant up there to heat that up. I would check the lines first and then the actualy heater core. Turn on your heat and see if you have a burning coolant smell coming out of the vents. I'm not sure on the S types but some of my previous cars have had a chute that if your heater core goes it will allow the coolant to leak out at the firewall in the area you are describing. I also have had the cars where it leaks in the passenger side footwell. Anyone know where they leak on the S type?? These are a few things you can check for now till someone else can chime in.
Also do you have an R or just the regular S type with the 4.2?? If its an R could be the coolant hose under the supercharger which is common and a pain in the a@@.

 

I think you hit it on the nose Vance.

It has to be the heater core/connections. I have the regular S type. I dont think anything has gotten inside the cabin on the floors so I must have an escape leak path. I will dig through my manual and see if I can find anything on the heater core.

 

Hopefully its just your connections I would definitly check those first as they will be the easiest to replace.

 

So I tried again to locate the leak by putting car on jacks and running the engine with A/C or Heat on. No leak at all this time. So it's kind of on again off again thing. If I have to take to dealer I want to be able to know it will leak when they look at it.

Also I need to verify if it's the heater core or an expansion tank. More investigating and searching this site needed.

 

I would try and jack it up level cause if it is the heater core the coolant probably just leaked and pooled inside where the heater core is since you have the front elevated. Also did you turn on the heat and smell the air coming from the vents once you had the car warmed up. Also you have to have the car at normal operating temp when you look for the leak cause you have to wait for the coolant to start flowing to the heater core which wont start will your thermostat kicks on which is why you have to wait a little while to start having heat when you have it on.

 

I had car running for over 20 minutes so I'm sure it was warmed up hot. I think you may have something about the level of the car Vance. I only had the front raised so if the core leaked you're right about it staying inside the box. Later when the wife drove it went back to bad leaking and smelling.

I'm trying to find a JTIS Manual for Mac but it looks like they don't make them. I have one for PC but now I'm thinking of finding cheap used PC just so I can load it since I only have Mac and at work PC wont allow downloads since I'm not admin. Still havent spent time searching forum but will try tomorrow. THX

 

Another way you can see if its your heater core is there will be 2 hoses that go into your firewall these are the lines that go to the heater core. You can disconnect them and get some coolant lines that are that size with some fittings and remove them from the firewall and use the extra coolant hoses you bought to connect them to each other basically bypassing the heater core. You wont have any heat if you do this but you can drive it around and if you leak and the smell has gone away you have your solution. Then its just a matter of getting a new heater core and then return it all back to stock.

 

Good idea.

Though, I did take the glove compartment apart and I think I saw 3 lines together coming into the core box from the firewall. One cold, two hot. But I didnt see any place to disconnect since they run right into the box. There is no outer connection. I could be mixed up but let me check again. Maybe I can do that trick in the engine compartment. More to come....

 

I can try and snap you a pic tomorrow afternoon. Mine will be a STR but should be close to the same.

 

I'm disapointed no one else on this forum knows anything about S-Type coolant behavior.

So the three lines going into the firewall Vance have two lines that are 5/8 and one bigger line at 3/4. At first I tied the two 5/8 together but then got a major leak out the open core firewall tubes. This meant that the big 3/4 was still introducing coolant into the core.

So now I used a tee and connected all three together. Well now no coolant appears to be disappearing but it's still early. With no A/C on everything works fine. When A/C is on it's still cold but a strange smell is detected. Hard to describe but funky plastic type smell. I will see if it goes away in a day or two. So if no coolant leaks now, I know it was the core or expansion tank (if I have one).

 

Quite possibly untrue. I don't see your car details so am moving on. Lots of others will do the same but won't even post saying so.

Also, I'd look up the details in the workshop manual.

 

Your A/C will still work since there is a flap in your dash that will switch the air from coming from your heater core area for heat and the area for your A/C. That flap will move when you change the temp. If you get no leaks its definitly gonna be the heater core. Nothing with the A/C system is involved with coolant in the dash so that should be good. Not sure why there is 3 coolant lines going into your firewall curious if you can snap a pic of that. Here is a pic of what the 2 that I have that leads to the heater core which is the 2 I was talking about connecting together. You will get some coolant coming out when you first start driving since the heater core is like a mini radiator there is coolant stored in it. As long as you arent getting it shooting out once its to operating temp then you have bypassed the heater core and if you get no leaks you know what you will have to replace.

 

In the first post he said he had a 2003 s type with the v8 cause I asked him if its was an R or not in case if was the line under the supercharger.

 

Yeah but who's gonna hunt back for the data? He's VERY lucky you did.

 

I see your point I only knew cause I have been the only one posting so when I first responded the original post was the only one.
You should just throw your vehicle specs in your sig. Its pretty easy.

 

I would put a white piece of paper or rag down to make sure what color the fluid is. Are you positive it's not the condensation drain for the A/C?? It drains on the passenger side behind the engine??
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You know what going back to his original post I pretty much missed his last sentence of it only leaks when the A/C is on. It sounds like it may be just condensation from the A/C system cause thats where it drips the water. You losing coolant may be it just filling up some air pockets you had when you replaced the reservoir. I would put the hoses back to the way they were and do this paper/rag method and see what you actually have dripping. I'll make sure I start reading post more then once before posting.

 

I have a leak. When I was driving the other day my "Low Coolant" warning came on. So I topped it and soon after a little driving it came on again. It does it sooner if I drive faster... Well, I did try to keep an eye on "where" it was coming from, and is really hard to see. Once the car is parked and turned off, it does leave a small water mark. Since the whole engine is covered underneath there is no way to tell exactly where it is from?

So today I took all of the covers off and went for a drive, and I can see Coolant running down from the top of the Transmission...

My car is an STR so it could be the hose under the SC, but do I have to remove the SC to replace it? BTW I the coolant I see running down from the top of the tranny is green, definitely not just A/C condensation...

Thanks,
JG

 

Sounds like you have the coolant line under the S/C leak. Here is an excellent write up on whats involved. Not for the faint of heart. On the last page is a pic of the hose attached to the engine. There are several good pics in the post on what to do. Now its just a question on whether you are gonna tackle it yourself or not.
https://www.jaguarforums.com/forum/s...ad.php?t=38911
To bad you arent closer to NC I'd tackle it for you so I could make a video for it. I'm going to school to be an automotive tech so kinda making my videos as a sort of portfolio.