Was on the way home yesterday afternoon, a balmy 30 degree day, and got a low coolant warning after efficiently but safely passing a few slower moving farm vehicles. Was about 10 minutes away from home at the time and made it home ok, coolant temp once home was around 197.8 F so it never overheated. The expansion tank was down to about 1/2 inch below minimum.

Filled expansion tank to mark, fired her up, let it run for 3-5 mins, revved it a few times, checked again, and it was down again. Looked underneath, and there was a drip, drip, drip.............. Without getting under it, my cursory analysis is that it is the thermostat weeping or a hose near it. I can see wetness around the thermostat. I can't find a leaking hose but I have not checked behind the engine.

I am leaning towards a turfed thermostat so I am posting to see what else the forum recommends changing while resolving this issue. Also, since it's a Volvo inline six, anyone knows the Volvo equivalent part numbers?

Some info, purchased it in December 2019 with 150,000 kms and it currently has 189,000 kms. Was going to do the thermostat this year anyway as preventative maintenance.

Part number I think is TH53290G1. Looks to be very expensive for genuine but there should be cheaper OEM available with a bit of luck!

Seem to recall an in depth report on i6 thermostat by p gill on here a while ago. Maybe of help.

Found the leak. It's the hose to the left of the thermostat (looking at the i6 front to back) and it looks like it going to a short aluminum pipe that looks like a cooler? It's definitely coolant that's leaking from it but why would there be a pre cooler to the rad itself? If it's the trans cooler then I have some serious confusion that I will have to work through, hello!!!! Maybe it's part of the heating system.

I will try to take a pic but the location is tough! From what I could find, it's looks like hose 18472B or LR005566.....


Did do a search prior to posting this thread and did come across p_gill's maintenance thread.

The most likely failure Is the coolant hose between the heat exchanger and the block.

On the end of the hose there is a plastic fitting that holds an O-ring

This is a known failure point.

If it were me I would start there and see if that fixes the problem.


Here are the part numbers

LR001442 - Coolant Hose for heat exchanger

LR000491 - Bolt for Heat exchanger hose

LR001505 - O-Ring for heat exchanger hose

And here is the link

https://www.freel2.com/forum/topic32245.html


Good luck

Paul

Here is a pic:

Click image to enlarge

Hi Paul,

To avoid confusing the parts guy at LR, what's the part number for this hose?

The picture helped a lot

Look at this thread

I am reasonably certain that you are looking at item 40 in the Volvo coolant hose picture

https://www.matthewsvolvosite.com/forums/v...mp;t=91980


Take care

Paul

Your hose failure is the first one that I have seen for that hose

I believe the part number you want is

LR005563

https://www.landrovermerriamparts.com/oem-...wtbDYtZ2Fz

If I were in your position I would do the following

1. Field expedient repair - cut the end off the broken hose and re attach

2. Look for the lowest price and buy the following

LR005563 item #17 (This should be the broken hose based on your picture)

LR005566 item #20 (it will be easier to just replace this hose while you are in there)

LR006071 item #21 (This is the right part number for the Thermostat, the LR catalog has the wrong number, be careful)

Click image to enlarge

Thanks for your help Paul! The hose I need looks like LR001442(6C755)



Since I am going the full monty and doing the thermostat as well your thread and help will get me the necessary parts by tomorrow morning. All ordered now, hopefully LR does not let me down. My parts guy gives me about 35% off list so, I'll one stop shop and resolve this issue ASAP!

That makes more sense.

My original recommendation was that hose and the O-ring.

It is a know failure point.


However it normally fails at the other end not the end you identified.

Let us know how it goes.


Take care

Paul

OK, job's now done....replaced 3 hoses, thermostat, manifold gaskets and new coolant (second time in a year, first was just preventative maintenance). The leak was the common failure hose, pictured below. I did re and re the injector rail, cleaned it up along with the throttle body.



A $38 dollar part...............

Very nice!!!!

I can see that the plastic part on the end of the hose did fail.

I am surprised that you didn't get a leak from that end first.


Nice work!

Take care

Paul

Yeah, managed to get all the broken pieces out...........now the dual Volvo fan added to the todo list!