I have a 1987 Jag xj6 vanden plas, I recently got it running and the exhaust was white smoke and the temp. was way up....I had had problems with the radiator and replaced it but when I had the bad radiator, my dad's friend put stop leak in it and all the time the radiator was plugged, so my question is do you think it settled in the hoses because a creamy white substance was leaking from new radiator? Need major help with this not wanting to replace head gasket...thank you

The problem here is someone did not respect the delicacy of the situation...ordinary tap water if frequently full of charge....what we need for the water part of the fifty fifty mix is De-ionized filtered water which will NOT react to the iron in the engine...creating the situation that you currently have...Rhizex particles intended to stop a leak at the radiator will play hell with coolant flow combined with already with the hot-spots and the overheating......sell the car.~.....okay, well brand new hoses (silicone preferred) a coolant flush (into five gallon buckets for environmental disposal) new thermostat and cross your fingers...maybe a plugged PVC valve ('bout four bucks) a vacuum leak to a critical system would need a thorough inspection of various systems for correct operation~

Just how intelligent is "your Dad's friend"...sounds like a carpet salesman~

found out not very "intelligent". thanks Dad....

Neilwillis said to run water through and then knock out motor seals....is this necessary or even hard to do?....

no...garden hose...breeze clamp and heat exchanger return...undo the plugs on the block and possilby on the heads as well...done this a few times 93-96 in Berkeley~

petcock at radiator base....remove~

as far as seals...what are you crazy, BOILING hot etylene glycol needs pampering?....this is just a garden variety flush~...of course to be chased with put the drain plugs back in and fill with 50/50 Glycol and distilled water~

pre-mix PEAK is a good one~

Excuse me for being not so knowledgeable....but I do not know where the location of the breeze clamp and heat exchanger return...plugs on the block and the heads....and the petcock. You have been the MOST helpful person I have found to help me with my car...not to many helpful people when it comes to my jaguar...thank you

well there are two hoses that go into the firewall for your heat-exchanger, for the defrost setting, for example...was suggesting that you pull off one of these hoses the flow out hose and connect your garden hose using a twirly-clamp~

1/8 scale of an XK-E was my first car...at the age of seven~

Jag87 do not be shy about not knowing....I really can never be absolutely certain about anything...but what works really works and is beyond reproach~

Owned a 77 Triumph Spitfire...if only it worked as good as it looked...they all have a "dragging the ass" single rear leaf spring which makes that poor feller sag (gives good handling) MINI's also have wierdo rear wheels in the name of quickness on the curves....takes all types...Do love the tenancies of various auto-makers to have their own set of unique flaws~

isn't this just a blown head gasket?

could be a cracked block...need further testing to pinpoint the source of the froth~

It sounds like a head gasket to me- the way to test for that is to do a compression test- I don't own a Jaguar though I have always liked the Vanden Plas especially- I cannot afford to keep one running

You could snug the head bolts a few degrees each following the torque table for your engine~

As the gasket disintegrates "loosens" the head bolts....change the head gasket or tighten them up~