Coolant Leak 2

[andypryce]

Ok, this car is starting to test my patience now. 4 weeks smooth running after big outlay on engine, then small issue with electric handbrake not working on one wheel ( easy fix ), but today after arriving home noted lots of steam and water dripping ++ underneath. Looking at the engine from the front the leak is definitely on the right side somewhere but seems to be at the bottom right rear of the engine. jacked up and peered underneath, I can see water dripping but no idea where from. So anyone had this? Is there a hose near the bottom of the engine near the back which is a known culprit? Will have to get it up on a ramp I guess to get a good look underneath.

[ptjs1]

Andy,

Do you know if it is water dripping (usual condensation from air con drains?) or engine coolant?

Paul

[andypryce]

Paul,

100% coolant, severe enough to drain the header tank in 5 minutes, which makes it all the more annoying that I can't see where it's coming from! Assume (hope) it's just a hose somewhere. Going to put it up on ramps tomorrow and take the splash tray off underneath to try and spot the source.

[J44EAG]

Andy,

Knowing a bit more about the back end of these engines than I did the other day, I suspect this issue could easily stem from the water feed pipes to the EGR valve. Leakage in that area could easily flood down the back of the engine and bell housing. There is one short elongated U-shaped pipe and the other is I believe the rear end of the valley hose which goes from the front thermostat area, along UNDER the supercharger, along the N/S lower rocker box before dog-legging around the throttle body elbow and linking up with the EGR valve. Those two pipes are awkwardly placed and secured on the EGR valve with those horrible squeeze type gas crimps. I had to cut them off with a Junior hacksaw. The pipes themselves were well stuck on and lack of space makes work in that area, extremely difficult. The nasty crimps were replaced with Jubillee clips.

If the valley pipe has gone, then the only option to gain access is to remove the charger. You will have no doubt seen my recent posts regarding charger removal and what a nightmare it can be. For your info, the valley pipe is 2W93-9F814-BC.

Hope that helps.

Mike

[andypryce]

Thanks Mike, I have read about the dreaded valley hose and really hope it's not that! In any case it is beyond me I fear...

[J44EAG]

Its easy if you are a thin two inch ferret on a six inch stick!

In the light of my recent experiences in this area, I strongly recommend professional help once you get to a grinding halt. Anything after removing the throttle body becomes seriously difficult.

Only two things worry me. My ex-wife and supercharger elbow removal. I`d take on the ex in preference!

Mike

[andypryce]

So the good news, I found the leak, see pic below, it is in the upper pipe behind the supercharger, the bad news is totally inaccessible, so I guess the supercharger needs to come off to get to it?

[J44EAG]

Removing the throttle body affords some improved access.

Two pipes go to the EGR valve and are secured with the dreaded gas crimps which I removed using a Junior hacksaw. Getting the hoses off the EGR stub pipes is not easy either. Replace clips with Jubillee clips. Size is about a 20.

Without doubt, the area around the throttle body is one of the tightest you will ever come across. Working there is most un-funny. The STR is even worse.

If stripping out has to occur, take the opportunity to replace as much pipework as you can and if the charger has to come off, change the oil and the cushion coupling.

Charger removal is easier if the thermostat and manifold are taken off at the front manifold to cylinder head to manifold joints. Seals will usually be ok for further service.

The big nause is that the elbow has to be removed to get at the back SC base mount bolt. The elbow has two bracket bolts right at the back at the base of the elbow. These must be removed. The nearside is easy but the offside is obscured by the EGR valve and the stainless feed pipe. That is where big removal difficulties start. Removal of the EGR has to occur to allow the elbow to be removed. Then you can get to the charger back bolt. It is buried deep down on the block valley between the cylinder heads.

The whole job is chicken and egg. It is a total nightmare.

Mike

[andypryce]

Sorted. New pipe (scavenged from an Alfa Romeo engine, as almost identical shape and size) fitted, he said it was a bit of a b****r to fit, but managed it, only £40 in total.

So what next I wonder.....

[J44EAG]

A good result, Andy.

In that area, most issues will be pipe related due to rubber disintegration caused by elevated temperatures around the charger.

The most famous failure point will tend to be the valley pipe. It is rather disappointing that Jaguar never designed that out on the 4.2. The pipe balloons about 2" back from the front end of the hose. It gets very soft and weak due to heat.

If not already done, can I suggest a charger oil change. That is easily done from the front. Being American, the charger sump bung is Imperial 3/16 hex Allen key. Oil is available from Powerhouse Automotive. Mine came out a little tired and blackened at 82k miles. The recommended oil change interval is every 60k miles. Use only the special synthetic Aeroshell 100 type gas turbine lubricant. £20 well spent in preserving the life of a £1500 supercharger. I`ve not checked the service scheduled to see if it is included in a 60k schedule. A syringe and small bore pipe is used to extract and replace the oil. Consult your Doctor for supplies of both!

Mike

[andypryce]

Thanks Mike, will add that to the list at next service, due soon.

[andypryce]

Mike, could you post a picture of site of s/c drain plug when you get a chance please, I will have a go at the oil change myself. Thanks.

[J44EAG]

Easily done, Andy.

Note the two front mounting bolt lugs through which bolts pass to secure the front of the charger to the engine valley. These are easily accessible when it comes to charger removal.

The screw in bung is immediately above the right hand charger mounting bolt lug.

Worth taking a look at the inverted charger case in this shot. The rear mounting bracket and bolt hole are shown top centre. Unfortunately the throttle body elbow which is bolted to the back of the charger completely obscures the rear mount bolt. Unless you can get the elbow off, accessing that third bolt is impossible. That is what bought me to a halt a couple of weeks ago.The thought of having to ever go back into that area makes me shudder just thinking about it.

Mike

Mike

[andypryce]

Thanks again Mike, just done 500 mile round trip, no issues !