So a few months ago I was having an issue with my 2010 XKR going into Restricted Performance mode. I also noticed if I let it sit for a week or so without cranking it, when I did crank it it would blow white smoke out the exhaust for about 30 seconds then stop. Well I took the car to the shop, and 1600 dollars later, they replaced all spark plugs, 2 coils, and did an oil change. Car was running fine. After about a week I noticed around every probably 8-10th time I would crank the car it would again blow white smoke out for a short period then stop. Car would run with no hesitations. I drove the car on about a 3hr road trip and on the way back my coolant low level light came on again for the second time in about a month. So I added coolant, and then the following day the car goes into restricted performance mode again, but this time after I get home and turn the car off for awhile, it came back out of restricted performance and drove fine again. Does this sound like a slow head gasket leak and that's what is causing my issues, or could it possibly be something else? Any help is much appreciated! Thanks

 

If your low coolant light comes on then we know there is a leak somewhere. So the question is where. Before we go to the worse case thoughts I would have the coolant system checked for exhaust gases and also have the water pump checked for leaks. If you have a bad water hose I would believe you would smell antifreeze or see smoke in the engine bay. Another option would be to drain the oil and look at it to see if it has a milky brownish color. Pending the results of all of this you should find your problem. Good luck

 

A little white smoke is typically just condensation and not a big deal. A lot of white smoke on an above 60` day is not good.

 

It's a lot of white smoke, thick white smoke. For about 20-30seconds then it stops. And it does it 3 every 8-10th time I crank it up, but will run fine. It never smokes from the engine Bay Area, just out the tailpipes. I know condensation lol and this ain't that. I would think when the shop changed my oil if it had fluid in it they would have told me, but you can't never really trust that these days.

 

As jagtoes said first check for obvious coolant leaks - coolant on the ground under the car after it has been sitting and around the water pump. Take the oil filler cap off and look for anything that looks like "root beer float" - a sure sign of a blown head gasket. If nothing obvious then check for exhaust gas in the coolant. You can do it yourself. A kit is about $25 or a shop should be able to do it for you.

 

If you are seeing white smoke from the exhaust I too would suspect a gasket leak. As you probably know, head gasket leaks usually means coolant in the crank case and can cause serious damage to lower engine components from reduced oil viscosity.

A solid way to tell if coolant is present in engine oil is to perform a blotter test. Put a couple drops of the engine's oil on a piece of blotter paper (back of a non coated business card will do). let it sit for an hour or two then observe the spot on the paper. If it is just a solid stain no coolant (antifreeze) is present. However, if there is a dark center or dogut shape image, coolant is present.

Testing by a lab would be the most accurate for determining if a leak is present.

 

Are you seeing steam or smoke? You need to check the coolant reservoir level to see if you are losing coolant. If not, keep track of the oil level. It is possible you could have a valve guide that is worn and allowing oil to leak into a cylinder/cylinders. This will burn off upon startup and produce a cloud of white-ish smoke.

Have you over-heated the engine in the recent past?

 

I'm pretty positive it's white smoke, not steam. Seems like steam wouldn't be as thick or present at a cold start up. I've looked for leaks under car after sitting and have never seen any puddles from leakage. I've had to add coolant 3 times due to coolant level low alarm popping up over about 1k miles period. It's never extremely low, maybe 20oz's or so. And it just recently started going into restrictive performance again like it did before the plugs, could, and oil change, but now if it does and I let it sit for a little while it runs normal again.

 

And no sir, I haven't ever overheated the engine.

 

Bummer, looks like you'll be digging into it. Some thoughts. You might want to verify it's not getting in via the throttle body or inner coolers as it's taken apart. Long shots but still worth looking at. Hopefully it's just a gasket issue and not warped heads (for whatever reason) but I'd have everything checked out while it's apart. Do you plan on doing it or farming it out? Other than the cam timing I don't think it's a huge job.

 

I have a extended warranty that covers the engine and all components/gaskets and what not, so I'll prob end up taking it somewhere. I can do the basic stuff, but wouldn't trust myself to tear in too deep.

 

Enroute I bet a bottle of good Tequila its not your head-gasket. If you win you will have something to sooth the aches. If I win you should be relieved.

Since you dont change your own oil, its safe to assume you would take this somewhere to have fixed. The danger in you diagnosing it as head-gasket is that the shop will agree with you.

 

Did you not read any of my previous posts? I never diagnosed this as definitely being a head gasket, I said possibly one, hence the thread for more insight on other possible issues. And I actually do do my own basic maintenance including changing oil. The only reason I didn't last time is bc it was already in the shop and needed it. I also stated I would be taking it somewhere since I have a warranty that covers most issues too in depth for me to tackle. Either way some tequila does sound good right now.

 

Do you have the ability to pressure test your cooling system? You say you have had to top off the coolant a few times, this seems to be the most urgent issue. You need to find out where it is going. Hopefully the pressure test will reveal an external leak.

You may also want to go see a shop that has the ability to detect hydrocarbons in the cooling system. If they are present, bad news...

If it is indeed white smoke then you have an oil issue.

 

Just pointing out the power of suggestion that's all.
You dont want the mechanic to think you are prepared to hear that its a engine rebuild job.
But that's you said you had warranty, get a new engine.

 

When dealing with diagnostic tests, it's best to perform two different tests and comare results.

To determine if there's a path for the coolant to enter the combustion chamber, remove the radiator cap when it's cold and then start the engine. If there is indeed a path, you'll see bubbles and if you get close and have a whiff, it'll smell like exhaust.

The second test is a bit more involved, but no more difficult than replacing a spark plug. Get a leak down tester and perform a leak down test. This will back up the above look and sniff test and isolate which cylinder(s) are leaking, and will also tell you if there are any other leaks from the combustion chamber such as the valves or rings.

As a side note, I suspect that as these cars are becoming more accessible for those of us that prefer to turn our own wrenches, you'll begin to see more DIY posts and technical discussions, and less "JLR warrantied my ____!"

Good luck and I'll be keeping an eye on this.

 

Try a combustion leak/sniff test on the coolant, it might give you an idea

BT-2 COMBUSTION LEAK TESTER KIT CO2 HEAD GASKET TEST BLOCK CAR VAN MOTOR | eBay

 

Thanks a lot fellas, I'm back at work offshore right now, but soon as im back on land I'll dig into it more and try out some of the tips mentioned! Thanks again.

 

Just an update from an old thread, issue did end up being a faulty head gasket at only 37k miles on the car. They also found a bad heater hose, and rebuilt the supercharger. Luckily I had a extended warranty so everything was covered, all 10.6k worth of work.

 

er Q&C, he is still looking for that bottle.

Though I've never used one, I guess extended warranties can be good!