Advice on Identifying and Fixing Coolant Leak in 2000 Rover 75 V6 2.5L

[brafaar]

Hi,

I would like to ask for your help in finding the root cause of a coolant leak. I own a year 2000 Rover 75, V6 2.5L, and live in Germany.

Over the past few weeks, I have been monitoring the coolant level and noticed it was decreasing. I had to top it up slightly every two weeks.

After investigating with an endoscope, I discovered the following:

1) The hose coming from the expansion tank (which later splits into two) has a 'bite' mark and a leak of a very viscous substance (it doesn’t seem like coolant but it might be). Does anyone know the reference number for a replacement hose? Is it difficult to repair?


Photo: Hose


2) There is an accumulation of pink sediments near the oil filter, and I also noticed sediments at the joint of the oil pump. Is it typical for coolant to be found here? I would expect oil but not coolant. Should I be checking elsewhere? Are there any usual suspects I should look at? Water pump?


Photo: 1) Oil Pump. The accumulation of sediments is in the upper bolt of the piece number: BZV 1181C
2) Oil pump union with another black piece where the leak seems to happen.



You are my last hope before I consider taking it to a garage and potentially facing a hefty bill to locate the leak.

Regards, Jorge

[Matt_75]

Hi Jorge,

I think the hose with the "bite" out of it is part number 8 on this diagram: https://allbrit.de/xepc.cfm?CAR=SARR...959&SPRACHE=EN

Regarding the photos of the pink substance, I think the first photo is showing the location highlighted in red here:



Is that right? If it is and the pink substance is indeed coolant, I suspect it's leaking from your Water Pump which is located here under the engine front plate:



Replacement of the Water Pump will involve removal of the front timing belt. Are your timing belts due to replacement? The service schedule is 6 years/ 90000 miles (145000 km). If they are due for replacement soon, I would do this at the same time.

[SD1too]

Hello Jorge,

For the hose with the "bite" mark have you looked at Rimmer Brothers' parts lists?

The pink sediment at the oil filter and oil pump are probably due to coolant draining from the 'V' through a gap between the water pump housing and R.H. cylinder head.
Coolant collects in the 'V' when the serrated clips on the straight plastic pipe have not been set properly or have moved in service. This results in the 'O' ring seals flattening and coolant leaking through them. The solution is new genuine Rover 'O' rings (CDU 3858) and positioning the clips fully outwards before tightening.

Simon

[Matt_75]

Simon's post raises a good point that I forgot to mention. Before launching into the replacement of water pumps and timing belts, check the 'V' of the engine for coolant leaks. Thermostat related leaks are probably the most common source of coolant loss on the V6.

[brafaar]

Hi Matt, Simon,

Thanks a lot for your help!

Despite my Rover 75 being over 23 years old and still in great shape with only 122,000 km (thanks to being garage-kept and used only on special occasions by the first owner) I've had it for 5 years now.

Unfortunately, I couldn't find the hose on the Rimmer Brothers website. Matt, I really appreciate the new site you introduced; it'll make getting parts easier as there are no customs involved I'm ordering that hose and their clips (parts number 12 and 13) today. Also, thanks for the photos; they're exactly what I needed to understand the engine better.

Today, I checked the 'V' with an endoscope and saw some pink and green/blue sediments, but I'm not sure if it's an actual leak. I'll take apart a few things for a better look next week and will keep you updated on what I find. I really hope it's not the water pump, as that would make things much easier. I'm also going to buy the O-ring to have on hand when needed.





Thanks again!

Jorge

[Matt_75]

Hi Jorge,

Happy I could help. The green/blue substance on your endoscope photo looks like it's built up around the temperature sensor. These are made from brass and this sort of build up is quite typical in my experience.

The other photo does appear to show some evidence of coolant staining the 'V' of the engine. However, it doesn't look severe enough to have accumulated enough coolant to spill over and collect around the oil pump, unless it perhaps sloshes over under acceleration perhaps?

Perhaps start by replacing the 4 thermostat o-rings as they appear to be leaking a little bit anyway. I would advise removing at the least the front inlet manifold as shown in post #4. If you do this, you will need a new gasket (LKJ100992).

Cheers!

[brafaar]

Hi everyone,


Just a quick update in case it helps someone else in the future.


It turns out the issue is indeed a leak in the water pump. Replacing it myself would be quite a challenge as I lack the necessary tools, knowledge, and space.


I took it to a garage, and they estimated it would take around 7-9 hours to replace the water pump, timing belts (all three), and change the coolant. The quoted cost is approximately 2000 € plus tax. This seems quite high to me, especially since the materials should cost around 200-300 € according to Rimmer Bros.


As I will have to change those elements, do you recommend changing anything else while they are doing the major job?


Regarding the hose, unfortunately, it's not available from the dealer mentioned earlier or from Rimmer Bros.



I'll keep looking for a new one and explore options to "repair" the old one.


Cheers!

[sean75]

I've just had this job done(timing belts).

I'd certainly look at changing the idler, tensioner + hydraulic plunger ( not always changed ) and as you've said the water pump.

Last thing you want is to find one of these starts to fail after it's all re-assembled.

Kits are available here via DMGRS or Rimmer Bros and no doubt a few more. You might wish to establish the age of the belts that are supplied as some have recently been discovered to be old stock. That's a whole other story though!

I paid circa £500 for the job although I would have no idea about pricing in your location. Depends on if they are familiar or learning on the job.

Good luck getting it sorted

[SD1too]

Originally Posted by brafaar

It turns out the issue is indeed a leak in the water pump.

I took it to a garage, and they estimated it would take around 7-9 hours to replace the water pump, timing belts (all three), and change the coolant. The quoted cost is approximately 2000 € plus tax. This seems quite high to me ...

Thanks for the update Jorge.

I hope that you have confidence in the garage's diagnosis because renewing the water pump involves a lot of dismantling and therefore expense. They will also need the special timing tools and that may be included in the extremely high price they've quoted.

Renewal of the idler wheel and tensioner pulley mentioned by Sean depends upon their condition which will be mileage related. The hydraulic tensioner is likely to be fine; mine had its 25th. birthday last month!

Your best bet is to give the work to a garage that has done a KV6 belt change before.

Simon