F-Type Coolant Leak

[jezzaaa]

Hi Guys - ok so first problem I've had with my F...got a coolant low warning. Checked the expansion tank, and it was indeed low. Topped up with the right stuff...and then parking up at the other end of a trip to the supermarket loads of steam coming out of the bonnet vents No overheat on the engine...temp gauge showing the usual central position. It's 15 mins drive to the shop, so a decent run. If the engine was starved of coolant, I'd have expected to see it get hotter...??

Checked the engine bay, and can see coolant down the back of the engine. Worried that this will be something complex/expensive. However, I did notice that there's a small hose going from the top of expansion tank and then to the top of engine and under the plastic top cover...and that it was completely loose and you could move it in and out of where it joins to the other larger rubber pipe. Thing is, it doesn't seem to be in a place where the coolant can be seen laying at the back of the engine.

I've done a bit of googling and it seems that there are some pipes running over the top of the engine, and at the back under the S/C which can become brittle and break over time. There was also some mention of a recall on the water pump and pipes in 2014...I don't know where that's located though so can't look to see if it's leaking in the right place.

Any thoughts/experience would be appreciated.

Cheers all,

J.

[reddiesel]

The Water Pump is at the front of the engine and the weakness is generally at the little plastic elbow on the front which can weep . You will need the Air Hoses in the Bay and the Serpentine Belt removed and possibly the bonnet to gain access . I have seen the job done and removing the Pump should be well within your scospe . As regards experience of leaks , across the two F Types I owned I had none . Personally I wouldn't think a water pump would be causing dampness at the rear of the engine so before removing I would be topping up and pressure testing to see if anything was visible in the bay or on the garage floor . It dont sound like big money to me and I suspect you may be on the right track with those brittle pipes and loose connections

Edited by reddiesel on Tuesday 10th January 17:13

[jezzaaa]

reddiesel said:

The Water Pump is at the front of the engine and the weakness is generally at the little plastic elbow on the front which can weep . You will need the Air Hoses in the Bay and the Serpentine Belt removed and possibly the bonnet to gain access . I have seen the job done and removing the Pump should be well within your scospe . As regards experience of leaks , across the two F Types I owned I had none . Personally I wouldn't think a water pump would be causing dampness at the rear of the engine so before removing I would be topping up and pressure testing to see if anything was visible in the bay or on the garage floor . It dont sound like big money to me and I suspect you may be on the right track with those brittle pipes and loose connections

Edited by reddiesel on Tuesday 10th January 17:13

Thanks Red...as you say, it doesn't sound like the water pump then if it's at the front. Hoping that any recalls on that would've been done by the first owner in any case (will check the service records).

I hope that brittle pipes over the top of the engine is what it is...the one that runs under the S/C is apparently a pain to get at and the labour costs can be a bit high. Anyway...it's gone into my local guy to have a look. I shall update

[reddiesel]

Fingers crossed you have a relatively cheap fix .

[jezzaaa]

Thanks Red. So I've been to the garage, and they've diagnosed a split expansion tank! So they're ordering a new one ... looking at prices in the UK it's a lot less than I feared. Seems to be a part in common with XKs, so been around a while. And an easy replacement. So with any luck, that'll solve it

[reddiesel]

Great News , to be fair the Temperature Gauge staying unchanged largely supported it being something trivial . I had the same issue with an X350 many years ago when the seam on the expansion tank failed . Of course it only really leaked when cold , as soon as it got warm there was no issue .

[jezzaaa]

reddiesel said:

Great News , to be fair the Temperature Gauge staying unchanged largely supported it being something trivial . I had the same issue with an X350 many years ago when the seam on the expansion tank failed . Of course it only really leaked when cold , as soon as it got warm there was no issue .

I'll believe it's fixed when I've driven it around for a while

[lexusboy]

If it’s on the back of the engine I’d be very suspect that it isn’t the expansion bottle knowing the location of it.

There is a plastic pipe on the back of the engine that goes from head to head which is plastic and I’ve seen a fair few leak from there

[jezzaaa]

lexusboy said:

If it’s on the back of the engine I’d be very suspect that it isn’t the expansion bottle knowing the location of it.

There is a plastic pipe on the back of the engine that goes from head to head which is plastic and I’ve seen a fair few leak from there

Pleased to report the original diagnosis was correct...expansion tank has been replaced and all fine

[reddiesel]

Great news

[Dodsy]

Afaik the Temp gauge wont tell you much , it works on a calculated average from the computer its not connected to any sensors. So it will sit mid gauge for a while even if engine is overheating . By the time it climbs to the top its probably too late .