MGB Smoking MGB

[daver80]

Hi all! I've got a 66 MGB that has been sitting for about 2 years without running. No real problems, just got sidetracked with other stuff (translated- kids) Had been running great last time she ran. Engine, head, have about 15,000 miles since rebuild. Put 5 gallons of fresh gas in, changed the oil, charged the battery and she started right up (with choke, of course) She smoked badly at first- white smoke, not as much later. thought it would clear, idled about 10 minutes after I shut off the choke (jets stick a bit, have to push them in after engine is warm). Seemed to idle fine but still too much white smoke. I cleaned out the barrels in the SU's- they werent dropping properly ("clunk") I checked my oil- no coolant in oil- looks fine, checked plugs, look sooty black from running with choke on, but not oil fouled. Any suggestions before I dig into checking the lifters under the intake and exaust manifolds. Maybe I should just let it run longer to burn more of the old gas out of there? Opinions? Thanks!!! Dave P

 

[DrEntropy]

Two words: OLD GAS!

Don't look for somethin' wot ain't there. Get it thru several "heat cycles" (up to normal temp) before making any decisions.

 

[daver80]

Doctor- Thats good advice I really didnt want to go poking around too much- she ran so nice last time I drove her. I'll try running more ogf the gas out of her.

We owned an 84 300D for 8 years, sold it in 2004 with 230k. Ran like a top. is yours light metalic blue? Dave

 

[DrEntropy]

Why, yes it is. Beast has well over a quarter on 'er, still putters along at 80 when asked. Took 'er on a 400 mile round trip this past weekend. Not a hiccup. Diesela's a good ol' girl. Bit "beamy" for my taste but <span style="font-weight: bold">strong</span>.

..."Brunhilde" wouldn't fit on a license tag....

 

[philman]

maybe you just have moisture in the exhaust system?

 

[vping]

Let er run and then change the plugs. I picked up a Bimmer recently, drained the gas and fired it up after a 5 years slumber. White smoke for a very long time and had me concerned. After running it for a good bit, she's fine. Bad gas and water in exhaust is what I attest it to.

 

[Stewart]

Give it 20 miles or so. My 73 smoked a bit at first and leaked oil like a sieve after not running for at least 8 years. After about 20 miles the smoke was gone and the oil leak slowed down to a silver dollar size puddle after being parked over night.

 

[daver80]

I think I'll back her out, fire her up, air her up and let her run her a bit. Sounds like no need to panic just yet. Thanks!! Dave

not quite as glamorous a list:
66 MGB
67 IH Cub Cadet 122
86 BMW R80RT (110k bike)
89 Volvo 240 wagon (206k)
and an old 70's snowblower

 

[glemon]

Does a 66 have that crankcase breather PCV valve? If the diaphragm cracks on this you can pull oil into the intake and get lots of white smoke, back in college I had a head rebuilt on my MGB before I figured that out!

 

[daver80]

Glemon- I'll check that out. All she has for emmissions is a disk shaped thing up on top with about 2 inches of tube. The plugs were sooty, but not oily. so I dont think oil is going into the combustion chamber, but I'll check that round thing- easy enough to do. Had it out twice now and still smokes. But I did get my turn signals working! Dave

 

[DrEntropy]

That disk shaped thing is what Glemon is on about. The wire "spring" widget holds the cap in place, under it should be a spring and a diaphragm with a small "billet" valve vulcanized to the center. The diaphragm should be flexible and unsplit, the funnel underneath clean and free of carbon deposit.

 

[daver80]

Dr / Glemon- I opened the disk (breather) tonight and saw a trace of oil in there, not a lot, but it was in there. The rubber wasnt cracked, but it wasn't new, soft and suple either. Those diaphrams are probably more $$ than I'm expecting, but maybe I should give it a try. At least price it out. Might even be a NAPA item- i might be suprized. Thoughts? Dave

 

[DrEntropy]

I doubt you'll find one of <span style="font-style: italic">those</span> at NAPA. If it has no cracks and isn't brittle it should be fine. A trace of oil is normal too. Run it some more. My vote is still on old gas. Run what's in there out and refuel. Then see if the smoke clears.

 

[daver80]

Ok, Doc! I'll do it! dave

 

[Ken Lessig]

That 2-inch thing on top is, in fact, the pcv valve mentioned earlier. You can undo the hose at the bottom of it, and check for oil in the hose; if it's oily there is a good chance the diaphragm is cracked. Another possibility is some rings stuck from sitting for two years; they 'may' free up after some more driving.

 

[RonMacPherson]

Or soaking them overnight(combustion chamber fill) with GM Top End Cleaner. Works great at getting the carbonbuildup off of rings.

 

[daver80]

Everyone who posted- BAD GAS! drained it all out the $2.23 gas (from 2 years ago)and refilled with $4.23 gas- and all is well (except for the $4.23 part) Dave

 

[DrEntropy]

mehheh. :laugh: