Hello Folks,

I have a 1990 XJ12 (I was advised to post motor queries on this thread, because most XJ owners have the 6 cyl model). If I run my car, I have white smoke that emanates from under the hood (Please see attached video).

The dashboard told me that the car was low on coolant, so I filled up coolant as per instructions in the owner's manual. I used a Prestone 50/50 mix. The car needed almost the full jug. My car recently also had some major ticking and so I put injector cleaner in the gas tank and that has since seemed to have resolved the issue, HOWEVER, when the car is set to park and idling it idles at around 1000 rpm, but if you put it in drive and idle, it idles at around 500 rpm or less. One or two times the car even idled so low that it stalled. Just before the stall the "battery light" will come on or flicker on the dashboard. Just after the video was taken I turned off my car for twenty minutes, and when I tried to start it again it wouldn't start. I had to turn the key and pump the gas once or twice to get it to start. After that one time it seems to start again every time with just one turn of the key. Please help!

 

Does it smell like smoke or antifreeze? It looks like a steam leak from the video.

 

Thank you for answering. It has a neutral, but slightly sweet type of smell.

 

If it's a sweet smell then it is antifreeze. You have a coolant leak. Could be heater hoses or head gasket.

Hopefully it's just a hose because if it is a head gasket you have a very expensive repair ahead of you.

Mark

 

It could be one of the hoses has a leak and Water/Antifreeze is dripping down on the hot exhaust pipe, which may explain the reason why you had to top up with so much Coolant.

And also explains the Steam.

 

In that area you have the following coolant hose joins and other joins:
1) heater radiator in and out (look on the firewall, hard to see but they are there!)

2) heater radiator outlet hose to steel pipe that goes along the inner wing to the radiator bottom outlet

3) auxiliary air valve seated into head casting (just behind cabin end of the air intake box

There is a good chance that one of these is either split or leaking at the clip, or the AAV sealing gasket is leaking. Unlikely it is a head gasket.

The tickover change you mention is not that abnormal, when the load comes off the engine when you select neutral, the revs will rise. Having said that, the AAV is probably jammed or not working as it should. repair/replace/fix. Lots of stuff about it if you do a search here.

Greg

 

See my answer in the XJ Series section a few minutes ago.

 

I now have white smoke coming out of the tail pipe when I rev the motor... Does that change anything?