LR3 Small Mystery Coolant Leak

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

ambrown31

Member
Joined
Apr 20, 2016
Posts
11
Reaction score
2
Hi everyone,

I have a 2005 LR3 HSE with 169k miles. I have been smelling coolant from the front of the engine for a while now and the level with drop very slightly every couple of hundred miles.

I replaced the water pump, thermostat housing, coolant reservoir within the last 20k miles. It is also not a problem with the bleeder.

I pressure tested the system and it looses about 2-3 psi over 5 minutes or so. I also use an airlift 55000 to refill the coolant and i can't get it to hold the recommended vacuum now. It will hold about 11 psi vacuum instead of 25.

I have used the airlift in the past to successfully refill after doing the water pump with no issues.

Does anyone know if the small upper hoses that go to the thermostat and throttle body should contract during vacuum like the large hoses do? They currently don't contract like the rest. I hear gurgling through those upper lines, the throttle body, and the thermostat area while it is losing vacuum.

Anyone have any ideas?

Thanks!
 

hell pie

Full Access Member
Joined
Aug 23, 2008
Posts
203
Reaction score
4
Did you try spraying soapy water on hoses and cooling system parts when you were doing the pressure test?
 

ambrown31

Member
Joined
Apr 20, 2016
Posts
11
Reaction score
2
I totally forgot at the time but I plan on trying that next. I am also going to clamp off some of the hoses and see if I can isolate the specific area where the leak is.

Thanks for the tip!
 

maxx4wd

Full Access Member
Joined
May 5, 2016
Posts
111
Reaction score
39
Mine leaks from the large o-ring on the thermostat housing (what a horrible design that is)...mine drips a few drops every few minutes and I just top off the tank every two weeks or so until I replace the o-ring yet again (seems like I do this every 30K miles or so) This time I'm going to use the 3m 5200 marine adhesive to seal the main plastic piping to that weird circle to square connection for the manifold and be done with it...I just have too many other things to do before then. I haven't pressure tested the system but have not noticed any increase in temps on the motor...but sounds like I might need to after hearing yours drops so much pressure and leaks far less then what mine has been doing for the last 6 months...
 

ambrown31

Member
Joined
Apr 20, 2016
Posts
11
Reaction score
2
Mine leaks from the large o-ring on the thermostat housing (what a horrible design that is)...mine drips a few drops every few minutes and I just top off the tank every two weeks or so until I replace the o-ring yet again (seems like I do this every 30K miles or so) This time I'm going to use the 3m 5200 marine adhesive to seal the main plastic piping to that weird circle to square connection for the manifold and be done with it...I just have too many other things to do before then. I haven't pressure tested the system but have not noticed any increase in temps on the motor...but sounds like I might need to after hearing yours drops so much pressure and leaks far less then what mine has been doing for the last 6 months...

Do you mean the part of the housing with the 4 bolts that mount onto the top of the engine block under the throttle body? I will have to check that. I could have an issue with the thermostat housing as well. I have used permatex products in the past and had very good luck with them on water pumps.

I went ahead and ordered an entire set of new hoses since I have so many miles on the car. Thought it would be a good idea regardless. Once I get them all on I will vacuum test again and look more closely at that housing.
 

maxx4wd

Full Access Member
Joined
May 5, 2016
Posts
111
Reaction score
39
Do you mean the part of the housing with the 4 bolts that mount onto the top of the engine block under the throttle body? I will have to check that. I could have an issue with the thermostat housing as well. I have used permatex products in the past and had very good luck with them on water pumps.

I went ahead and ordered an entire set of new hoses since I have so many miles on the car. Thought it would be a good idea regardless. Once I get them all on I will vacuum test again and look more closely at that housing.


Yes that is the housing I am referring to - the o-ring connection just after the 4bolt plate to the circular housing is where I have the most issues with mine.
 

remember5

Full Access Member
Joined
Nov 26, 2014
Posts
408
Reaction score
126
I've replaced every component from radiator to pump to reservoir and still intermittently smell coolant near the expansion tank but cannot find a leak. I hate the whole cooling system design. Too much plastic.
 

proslambanomenos

Well-Known Member
Joined
Apr 21, 2013
Posts
47
Reaction score
2
i've been experiencing a similar thing. not sure if it's the same cause. i spoke to a seasoned lr mechanic and he said the cardboard gaskets in replacement pumps can leak, and to make sure you get one that is metal. the pump i replaced last summer from autozone (only one available at the time) indeed had a cardboard gasket. i haven't gotten around to changing it out again yet, so i can't confirm, but thought i'd pass this along if it aids in your diagnosis.
 

ambrown31

Member
Joined
Apr 20, 2016
Posts
11
Reaction score
2
Thanks everyone for the suggestions. I was able to finally resolve this. It turned out it was the water pump. Very surprising since it has probably less than 15k miles on it. It was an Airtex replacement that had the cardboard gasket. I think it was leaking at the shaft seal though not the gasket.

Hoping to find a better pump I bought the oem replacement from roverparts, and was surprised to find when i opened the box that it is an Airtex. The one from roverparts did have a metal gasket though but the rest of the pump looked the same. Time will tell if it will hold up any better.

If anyone has any suggestions for high quality water pumps that last let me know. Dealer gave me a quote of $420 plus tax for their pump and I am not interested in paying that.

One last tip, I finally found my leak with an automotive stethoscope. Probing around the cooling system while i had a vacuum pulled and as soon as i touched the water pump pulley it was clear that's where the leak was. I would suggest picking one of these up. Cheap tool that is very handy.
 

hell pie

Full Access Member
Joined
Aug 23, 2008
Posts
203
Reaction score
4
I replaced my water pump earlier this year with one made by GMB. It was less than $50. A lot of the Jaguar guys say that the water pump needs to have a plastic impeller, not a metal one, due to cavitation issues.
 

Latest posts

Members online

Forum statistics

Threads
36,223
Posts
217,601
Members
30,474
Latest member
sawcut
Top