Smoking Gt Junior!

[jason156v6]

Dear All

My GT junior is a bit of a smoker and is due an engine rebuild which I hope to get started in the next month or two. Usually it puffs a bit of blueish smoke on a closed throttle after acceleration over 5000rpm, anything under that she's fine. I am aware of the issue and thats what prompted the rebuild plans but this weekend a new form of smoke appeared....

Took the car for a good run then after a fairly long downhill run (2 miles or so) I pulled into a petrol/gas station and filled her up. As usual I blip the throttle slightly before turning off the ignition but on this occaison I probably revved it higher than normal. Filled her up and then started the engine, lots and lots of white smoke started pouring out for 20 seconds, enough to cause a bit of alarm at the station. A few moments later it cleared and I drove off, and the car felt fine.

I drove straight home and checked oil levels and they were OK. I gave the car a 20 min cool down checked water levels (slight smudy stuff on the radiator cap) and restarted the engine.. lots of white smoke again but for a shorter timeframe. Took the car for a quick spin and once on the road felt fine and didn't smoke. A further drive that evening and no smoke at all.. confusing and worrying.

Any ideas of what this new smoke is? Impending head gasket failure?

Appreciate your opinions -

Thanks

Jason

Hong Kong

[Fletch]

With alot of white smoke, sounds like a failed head gasket.

[papajam]

It could also be brake fluid from a failed servo(s).

[frogeye]

White smoke often indicates coolant in the water - as it is now OK it could very well be hydraulic fluid. Matt

[Blue Flame]

Clamp off the vacuum hose to the booster and see if it does it again. Careful, no booster assist on the brakes.

[Bill S]

Quote:

Originally Posted by jason156v6 Dear All My GT junior is a bit of a smoker and is due an engine rebuild which I hope to get started in the next month or two. Usually it puffs a bit of blueish smoke on a closed throttle after acceleration over 5000rpm, anything under that she's fine.

[frogeye]

Bill, To the initial problem ,yes valve guides are the most likely cause of the bluish smoke. The white smoke could be coolant or it could be hydraulic fluid. Matt

[jason156v6]

Thanks for all the answers, and they are very helpful

It looks like worn valves and piston rings are the key suspects for the "blue" smoke which has been on and off for a while... and coolant/gasket seem likely for the new big "white smoke" on some warm start ups - but the hydraulic fluid theory is interesting. Given that I had already decided to do an engine rebuild (not this soon though!) I don't wan't to discount this viewpoint.

White smoke was pouring out (upwards/skywards)) from the exhaust.. would that be water/steam causing the upward motion?

Any ideas how I can could determine or rule out the hydraulic fluid issue?

The car had its "head off" 3 years ago but no bottom end rebuild ( it could be a bad gasket seal) .. its done an estimated 129K miles so it is fairly tired and my mechanics told me that pistons an liners slipping oil are a likely issue. I got used to the blue smoke over time but the new huge cloud of white smoke this weekend suggested something new and more serious

I really appreciate your opinions and experience

It looks like an engine rebuild coming up - thanks Visa card! but any opinions on the hydraulic issue welcome

Many thanks

Jason

Hong Kong

[frogeye]

Do as blueflame suggest and clamp off the vacuum hose to the servo

[jason156v6]

Quote:

Originally Posted by frogeye Do as blueflame suggest and clamp off the vacuum hose to the servo

[Bill S]

Again, have that compression check done with the throttle plates wide open. You might only need a set of valve guide seals (doesn't even require removing the head) and a booster diaphram. Wishful thinking, I know, but sometimes it turns out to be the easy answer. Good luck.

[alfaman1963]

Hi Jason Not to discredit Bill but a compression test can not determine bad valve seals or guides for that matter, {they would have to very damaged}. In fact oil coming down into the combustion chamber may actually increase compression. This is a typical systom of a cracked head OR headgasket..Drive the car get it hot let it sit for 15 min or so and then remove the spark plugs and look into each cylinder with a small flash light. You may need to push the car in 5th gear so the valves will not block your view. You will see coolant in a cylinder or steam. Then have somebody crank the starter and see if any moisture shoots up......Good Luck Jim
PS also by looking at your pictures I see you have an aftermarket headgasket,notorious for coolant leaks........

[crashmctavish]

And stop revving it before you shut off, it washes all the oil from the cylinders!
White smoke = Brake booster
White steam = Water
Blue smoke = Guide seals or rings

[Bill S]

Quote:

Originally Posted by alfaman1963 Hi Jason Not to discredit Bill but a compression test can not determine bad valve seals or guides for that matter, ...

[jason156v6]

Thanks for all the extra replies all appreciated. Forums like this really help you to
get a number of views and hopefully narrow it down from there.

I'm going for the rebuild, with the mileage on the car and no intentions of getting rid of it, I thought i might as well go for it and get top and bottom done. Its also the hot and rainy season here now so timing is good

After the mechanics looked at car they felt #1 suspects were: for the occaisional blue smoke... worn piston rings (but they didn't discount valves either!) and for the white smoke/steam, possible head gasket (radiator cap has got a small amount of "sludge").

Parts are ordered and car bookied into garage, the work will begin in a couple of weeks - I'll definitely post up some pictures of the strip down so all can see condition of gaskets/valves/pistons etc.

I've also stop "blipping the throttle" after Keith's advice - previous owner told me it would help it to start easier next time - I stopped doing it and it still starts fine so good advice.

I'll be back with the photos soon

Thanks all