Hello good folks, hope you all keeping well in these difficult times.
Speaking of difficult times I took my 1996 xk8 to the mechanic to have him install a new radiator. Anyhow he runs the car for 15 mins after installation to check the oil pressure is good then shuts icar off as the temp needle stayed level. Shortly after that we lifted the car to look underneath and notcied a very bad coolant leak from the back portion of the engine. Mechanic believes it is coming from the, "one-way pipe (heater pump to valve)" that has blown and states its a common problem. Mechanic then proceeds to show me the part to replace on E-bay, nice and cheap, and says the car will be safe to drive home as the cold air blowing though the rad will cool things down and it won't leak as bad.
This was late Friday afternoon so I drove the car home and today being Sunday pulled the car out of the garage to continue with some interior restoration and decided to check the coolant level. Coolant is now a milky brown. So after a brief internet search as to faults I'm thinking a blown way one pipe which then leaked wouldn't casuse the colour of the coolant to change or would it?
This of course leads onto the worst case scenario,a blown head gasket allowing oil into the coolant system. Also just reversed the car into the garage and it sort of jumped while reversing. Gearbox fluid issue now? Any help much appreciated.
Regards
S. Degenkolb

 

My first thought was indeed oil mixed in with the coolant but I certainly hope that is not the case. Does the coolant feel more oily than usual when rubbed between your fingertips?

Did you smell coolant coming from the exhaust tips when the engine was running?

 

[QUOTE=St. Stephen;2364978]..... I took my 1996 xk8 to the mechanic to have him install a new radiator. ..... lifted the car to look underneath and notcied a very bad coolant leak from the back portion of the engine. Mechanic believes it is coming from the, "one-way pipe (heater pump to valve)" ..... and says the car will be safe to drive home as the cold air blowing though the rad will cool things down and it won't leak as bad.QUOTE]

ACTION PLAN
1. get a new mechanic. Anyone who recommends it's safe to drive an XK8 with a bad coolant leak is incompetent.
2. if you followed the advice, start browsing for "used engine with warranty".
3. be certain of the precise cause of the fault before spending any money.

You may be lucky and it is only hose(s) but if not, engine and transmissions rebuilds are seriously expensive in parts alone even before considerable labour costs. Once someone starts that type of work, you are almost locked in to letting them complete it so choose carefully.

Graham

 

It could possibly mixed coolant types. If there wasn't the milky brown coolant before the radiator change it could of been refilled with a different type of coolant than what was in the system.

 

Many brands of 'STOP-LEAK' type additives can make the coolant a 'brown-color'.
Maybe it was added to help get you home?

 

That would be the best case. Check the dipstick to see if coolant has made it into the oil, and if not flush the cooling system, refill with just water, then run the engine for a half hour or more while keeping an eye on how much is leaking. If the water stays clean one of the Bobs is probably right.

 

Cheers and thanks for your advice and help folks
I have checked the oil dipstick and the oil is clean. The mechanic's didn't put a stop leak in to get me home they just said it will cool down when driving due to air intake through radiator so that rules out a stop leak addative.
One consideration is mixing coolant brands. I say Brands and not types, at least I thought not types.
It was running happily on Jaguar anti-freeze JLM209723 which is an orange colour but I found this expensive so looked for a cheaper alternative. To that end I found Halfords OAT Anti-Freeze and Coolant which is a pinky/red colour. So I cheerfully mixed up some of the Halfords own brand thinking that it was the same as the Jaguar brand, both being OAT. I must add here after considerable amount of research too.
So after the raditor was installed the mechanic then proceeded to mix up the coolant I had supplied with the existing Jaguar JLM209723 coolant already in the system.
Have I caused this fault by mixing 2 different types of anti-freeze thinking they were both OAT and therefore the same?
Thanks in advance

 

If mixing the coolants proves to be the fault, would this mistake interfere with the transmission? As I mentioned above the car jumped while I was ibacking it into the garage.

 

Mixing coolant of different specifications in these Jaguars is never a good idea. I would drain all existing coolant and replace with the proper product....

 

UPDATE some hours later. After double checking I just wanted to make sure both Brands of anti-freeze were OAT and YES. So my logic tells me they should mix just fine. The Jaguar own brand JLM209723 which is also Ford WSS-M97844-D and the Halfords own brand are OAT. ( Organic Acid (Additive) Technology )
Tech specs, both are ethlylene glycol - more specifically Jaguar brand is Mono Ethylene Glycol ( Mono Ethylene Glycol, commonly referred to as Ethylene Glycol Antifreeze ) whilst Halfords brand is just Ethylene Glycol.
Just confirms my logic, they should mix just fine.

If I'm wrong please explain to me why?
Also how long can I leave this latte coloured creamy coolant in the car? I'm not going to drive it and I have busy week ahead and no time to flush it until next weekend and I don't want the coolant to gel or some such thing.

 

FWIW, looking at the cooling fluid just sitting there on the expansion tank from the top makes it look brown. Take a sec and dip a paper towel in to double check the actual color. I use Dexcool, it looks brown, but a dipped paper towel shows bright orange.

 

Thanks and I wish that was the cause. No such luck.

 

96-99 cars came with green coolant. mixing 25 year old green coolant with orange can give you a nasty brown.

 

You may be using the correct coolant as per jaguar specs.The prevoius owner could have changed the coolant to a dllifferent type. If the PO flushed the system and then added any coolant it would not have gelled or become cloudy until a different coolant type was added.
If I was in your situation I would drain and flush the system and then add plain water. Run it for a couple of days and see if the milky brown color returns. Of course repair your leak before driving.
I wouldn't drive it with the milky brown coolant. If it is gelled you might cause blockages and overheating. It is not good for your new radiator.
You can do a compression test to see if you have a bad headgasket.

You didn't mention why you replaced the radiator. Was it leaking or not cooling properly?

 

As I said earlier the coolant in the car was already orange Jaguar WSS-M97B44-D OAT and was running fine and has done for quite a while.
Slight correction - Jaguar V8 engines from start up to MY 1998.75, essentially pre-99MYs, used Ford spec DOW D542 coolant which
is the traditional green fluid. There is no chance that I mixed green coolant with orange, though thank you for your input and help.

 

Hi and thanks for your input. I replaced the radiator becuase the car was going into the shop to have the radiator support bracket starightned out as I had used it quite frequently to jack up the car. After straightening it I had the mechanic weld a rectangluar bar the length to the bracket to avoid that issue in the future and thought while I had the old radiator out I would put a new one in.

 

This why I'm confused. You mentioed new radiator.
Still I would drain the system as much as you can. Do your repair and add plain water. You have to get the milky coolant out of the system anyway. See if the milky brown comes back.
If you are sure it is not mixed coolant do a compression test.
Hope it is mixed coolant because a headgasket it a bigger pain to deal with.

GOOD LUCK.

 

+1 to the flush and fill. No evidence of coolant in the oil is a good sign but you need to:
1. resolve the source of the coolant leak
2. get the brown mixture out of the cooling system

The Jaguar V8 can overheat and suffer irreparable damage (warped heads) very quickly. The leak has to be the first priority.

Next clean out the cooling system:
1. drain
2. fill with plain water
3. run up to temperature
4. set the AC to max hot to circulate water through the heater matrix
5. cool
6. repeat 1 to 5 until it comes out clean

At this point you can safely use any coolant of choice with no risk of incompatability. As OAT has a 5 year change interval, a quick calculation of the cost of fuel over that same period leaves me unconcerned at the price of Jaguar coolant.

Graham

 

I'd be amazed if mixed coolant types could have that much effect in such a short drive. You definitely need to find a new mechanic, as others have said - his idiotic advice could well have cost you an engine. Even if not, I would not let someone with so little mechanical knowledge anywhere near a car of mine.

 

Update
Turns out this is probably a faulty new radiator which has an internal crack or break resulting in a mixing of the transmission oil with the coolant.
I say new raditor because it was new but part damaged as it had a few slightly bent fins therefore sold as damaged new stock on E-bay. Upon installation we notcied a couple of mounting brackets were sheared or broken off. Me not knowing that transmission oil was flowing through a raditor as well as coolant said, ok, we can still use it by fabricating new mounting brackets which we did at the mechanic's shop.
Now, please be gentle here. One of the reasons I bought this car was because I knew nothing about cars so I bought a cheap non runner off e-bay. In that time I have repaired more things wrong with it that I care to mention BUT I must confess in my niavity I thought a radiator had one job and that was to cool down the engine coolant not do 2 jobs at once by cool down the engine coolant and the transmissin oil too. Had I known that I never would have risked putting a part damaged radiator into my car and run the risk of mixing oil and water. That much I do know.
Ok, so this is where I am now, tough lesson but I will overcome, somehow. I am neither rich like some members on this forum with multiple Jags or as some others, a history of many previous Jags. Don't tell me to get the transmission rebuilt by a pro in Scotland or elsewhere. Think Apollo 13. I have a ball of string and some tape. How do I get this car to drive again, bad analogy I know but not too far off.
I am poor working class so I am looking to do everything on this car as cheaply as possible and for the last 18 months have managed to do so very successfully. To that end the first job I did on this car was brain surgury to the ECU with a blown capacitor by taking it to a TV repair man to solder in new capaicitors.
About £50.00 for that job compared to £300.00 to £1000.00 elsewhere depending on who does it.
If your going to tell me I'm in the wrong type of car DO NOT REPLY to this message and move on, it's not helpful.
I need to flush this transmission or do a 3 time fill and refill. Whatever is the cheapest and best option please. I will deal with the coolant issue first after I take out this damaged radiator and put my old one back in.
Who the hell thought mixing oil and water in one container would be a good idea? No chance that can go wrong is there. pissed off.