2008 Super 8 with 28,000. I smell coolant when car is hot for the last few months and the level goes from topped off to coolant level to low warning light in about one a month. Operating temp is solid on second bar from bottom. We drive it about 200 miles a week.

I replaced the coolant tank and cap but did not solve problem.

I asked the guys at the *********** about the coolant hose under the supercharger and they said they have never heard of a bad hose on the 2008. I live in South Florida so heat is normal.

Does anyone have any ideas what it could be and the best way to diagnose this problem?

Thanks

 

Sounds like you have a stuck open thermostat with the gauge not in the middle. With a good thermostat the gauge should sit in the middle.

It may also cause the coolant smell and "missing" coolant as described if we assume that there is no leaking hose. This is because it act kinda like no thermostat and the coolant is flowing too fast thru the radiator and doesn't have suffiecient time to stay in the radiator to cool off but this is very unlikely because the opening of the stuck open thermstat is small enough to restrict the coolant flow to a slower speed so in theory this circumstances is unlikely but some possibility.

Check the upper hose from the thermostat housing that goes to the top engine block and see the connection there. The hose is one of the bigger but short 90 degrees bend hose that are maybe only 4-5" loong. Look at the side that goes down to the block there just right underneath of the supercharger snout.

 

Have a look at the expansion tank where the small hose connects, right next to the bleeder screw. You will probably need to remove the hose clamp and hose and after doing so inspect the nipple. I've seen these crack causing a very minor leak. You get the smell but often times not much coolant dripping so it's pretty easy to overlook. Have a look and let us know.

 

Thanks for the replies. The expansion tank is new and it included a new cap, stubs are new. Hose connections are not leaking. The old one did have the red residue like you are pointing out.

Correction on the temp. Its my wife's driver, so I took another look. It is in the middle. I counted bottom line as zero (blue zone) and didn't count the 1/2 lines. SO it is in the middle (normal) of the gauge, or the 4th line total, including the 1/2 lines. No temp issue.

 

If you smell coolant then you definitely have a leak, just a matter of locating it.

Could be the water pump seal, and if it's that small it'll likely be evaporating before you ever see the coolant. Hard to notice the white residue around that area of the engine. You should pressure test the cooling system (when cold) and see if you notice any drips around the wp or any other connections.

 

I will take a look at every bodies suggestions and get the car on a lift to see if there is coolant running from rear of motor....the hose from under SC ends up there.

Thanks forum. Please keep suggestions coming.

 

Pressure checking the system has been my preferred diagnostic procedure with my XJR. Kit is available for tool rental at most parts stores.

If you can smell it, it is leaking and with an aluminum engine, catastrophic failure of the cooling system quickly becomes very expensive.

My (recent) experience with the under S/C leak is that you can smell it for quite a while before any coolant reaches the ground. When you get a wet spot (any wet spot) on the driveway, it's time to park the car and make the fix.

Bob
Liberty MO

 

Remove the plastic shield that covers the bottom of the vehicle and look for radiator fluid. Press on the oil absorbing sponge in case it is absorbing any dripping radiator fluid. If you have a dripping type leak you should be able to detect it this way and about where it is dripping.

One hose that is prone to leaking is the small finger size hose that goes from the EGR valve to the throttle body. To see it you will need to take the plastic cover off the top of the engine which is very simple to do by turing each of the four bolts one half turn to relase it. Coolant flows through this small hose to cool the EGR and trottle body (wow such a high tech engine) and is prone to leaking at the fitting ends. Part number AJ811761. Check it when the engine is hot and the system is under pressure.

 

Be aware that there is a line that goes under the SC that is known to leak. Its an 11 hr rated book repair and you have to remove the SC to get to it.
My mechanic here in Orlando could probably help you Findre if you still need assistance, he just did one of these.

 

I suspected it may be the SC hose and when I bought some extra coolant I asked the service techs about the SC hose problem. I was told that this was a problem on the older SC cars but they didnt see it with the 08-09's. It made sense that Jag would fix a problem like this over time, especially if it was being covered under warranty. A coolant smell is a coolant smell and all the good thoughts won't change a bad hose under the SC.

Anyone hear that the SC hose is limited to the older SC's?

Also, I heard there is a line that goes to the oil filter housing. Is that prone to leaking?

I still smell it but it is hardly losing ang coolant. I havnt added anything in well over a month....over 1000 miles.

 

I believe the one my mechanic just worked on was a 2009? ...not positive though. I do know the guy purchased one of those extended warranty deals (some deal) and since its a hose, they don't warrant that.

 

The J@g de@ler tried to sell me the extended warranty for 4,000. I figured anything that went wrong I could fix for way less than that. Car had 26k when I bought it. IF I have to pull the SC, I will replace the pulleys with HP ones. If I can find a Dual Stage SC, I'll put that on.

Like I told my wife, if Super8 becomes a problem, Ill pull the seats out, put a HP SC in, remap ecu, bigger injectors and a set of Sparco/Recaro seats and then off to the track to drift.

 

Don't be surprised if the new expansion tank is bad. A pressure test will tell the story.

 

Sounds like the same issue I had just before the hose under the supercharger failed. I had the smell, but I had already replaced every hose and the expansion tank. Finally, I came out one day and noticed a little orange under the car in the transmission area. That meant it was leaking down the back of the engine, which is where that hose failed on mine; at the back of the engine block.

Granted, I had 108K miles at the time and is a 2004 that spent it's first 4 years in Miami.

Good luck.

Mark