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Mon Jun 25, 2012 2:52 pm

Hello All,

Here's the story. I have a 73 with a T4 engine. The last couple of weeks the bus has been hard to start when cold, lots of cranking to get it going. So last weekend the heat finally broke and I decided to track down the problem. Got the bus started with a lot of cranking and pumping the gas a little. I let it warm up for a minute or two and reved the engine a bit because it hasn't ran in about a week. The engine sounded a little rough and the rpms seemed low. I walked to the back of the bus and noticed a large oil puddle growing larger by the second! (not just a few drips but practically running down from the rear of the engine by the fan) I ran back up front and shut it off quickly. I wiped the under side of the engine down and looked for the source. The dipstick boot and where the engine meets the filler pipe were both leaking bad. The most of the drips were coming from the areas circled in the photo below.

I can see how oil can make it over from the filler pipe to the blue circle but the red one? Above that side seemed pretty clean.

I wish that was the end of my story but today I woke up to find a 4ft dia. oil stain under the bus! I removed the valve covers and oil came pouring out.

I'm in way over my head here and could use some good advice of what to do. I'm worried that the hard start issue has either led to the leak by over cranking or the two issues are related somehow. I haven't started the bus since it started leaking. Any advice would be great.
Thankyou, Martin

Mon Jun 25, 2012 3:03 pm

If oil dripped out of the rocker box when you removed the valve cover either the engine wasn't sitting level or you had greatly over filled the crankcase.

Mon Jun 25, 2012 3:07 pm

do you have carbs or fuel injection?

was this oil watery, like maybe there was gas in it?

Mon Jun 25, 2012 3:22 pm

The bus is parked on a slope. It has a single weber progressive. It appears to be pure oil. I did an oil change late April and have put on about 500 miles since.

Mon Jun 25, 2012 3:22 pm

with the lack of varnish and oil on the rocker arms it is likely rustbus is correct and there is gasoline in the oil.

Tue Jun 26, 2012 8:25 pm

Ahh Yes. There is gas in the oil. The carb was leaking pretty bad and there was alot of fuel spillage on the top side of the engine. I was so sick over the oil leak underneath that I never looked up top. Well I pulled the carb and drained out all the oil. I replaced the dip stick boot and put a seal on the filler pipe where it meets the engine. (there wasn't a seal here to begin with). I think the single progressive is going to have to go, it's been nothing but trouble.

I just have one question. I will be replacing the float and the needle and seat(again). Do you think it would be ok to start it up for a couple minutes to check for leaks or should I pull the engine and tear it apart?

Tue Jun 26, 2012 9:32 pm

I don't see much reason to pull the engine at present. Drain the oil and filter and fill with new oil.

To check your old needle valve, pull the lid off the carb and invert it, then try to blow through the fuel inlet. You should not be able to blow through it.

Maybe try setting your float a little lower, at least a 1/16 of an inch and maybe an eighth. A float that is set too high is going to cause gas to drip through the carb when the engine is shut off.

Tue Jun 26, 2012 9:37 pm

Sounds symptomatic of a blown oil gallery plug on the back of the engine. Except for oil at the rockers.

Tue Jun 26, 2012 10:07 pm

On the plus side, you now own the cleanest set of heads on the Samba. :D

Tue Jun 26, 2012 11:12 pm

Not to be a bearer of bad news but maybe some reality. Gas disolves sealant. At least the Permatex Aviation that many of us use to seal our engines. The greater concentration of gas in the oil and the longer it's in there can sprout engine oil leaks. How do I know? Delt with it last year and it took a bit of work and coin to resolve. Anyone have a need for a few gallons of brand new oil with gas in it?

Tue Jun 26, 2012 11:19 pm

Desertbusman wrote: Not to be a bearer of bad news but maybe some reality. Gas disolves sealant. At least the Permatex Aviation that many of us use to seal our engines. The greater concentration of gas in the oil and the longer it's in there can sprout engine oil leaks. How do I know? Delt with it last year and it took a bit of work and coin to resolve. Anyone have a need for a few gallons of brand new oil with gas in it?

DBM - I thought you had a stock carb? Did the float jam or the pump rupture?

Tue Jun 26, 2012 11:29 pm

Webers on the bus.
We already went round and round with floats, settings, float materials, new floats, multiple rebuilds, jets, fuel pump, plumbing, possible heat, thermal expansion, and ambient heat cycling and all that stuff.
After months of fighting my solution has been a shutoff valve in the tank line. No problem now plus fire protection.

Wed Jun 27, 2012 8:28 pm

OK OK!! Replaced the needle and seat and reset the float, put the carb back on. Filled it back up with oil and TADA!! no leaks present :D Ran it for about 20 minutes trying to bake the oil off the heat exchangers. I clamped off the fuel line for now but sooner or later I'm going to have to see if I still have fuel leaking down. (I'm still shaken from the situation). I think i"ll look into a cut off valve as D. Busman did. There will be no long trips this summer. With all the dry conditions it seems like a bad camping season anyways. Thanks guys for all your the input.

Martin

Wed Sep 26, 2012 6:01 pm

Ok folks I'm back again with the same issues. I thought I had the problem solved with my progressive carb needle and seat. About a month later I installed Weber ICT's and they started out awesome with no issues for about a month. About 2 weeks ago the engine was flooded with gas again. I have changed out the oil and put a fuel shut off valve before the tee. I have also added a regulator and gauge. (I've been doing a lot of reading on here lately.) But I degress. Since then my engine hasn't ran the same as it used to. I can't seem to get it to idle correctly and seems to have a dull clunking sound as the engine turns.

Here's what I've done so far. (1700 T4 with dual weber ICTs)
Changed oil and filter (again)
Checked Timing: 29 Deg at 3200 RPM
Adjusted valves to .006 in (#1 and 3 were tight 2 and 4 were fine)
Compression test results:
#1 110 psi
#2 105
#3 110
#4 100
Changed out the plugs (old ones were fouled)
Checked carb sync and idle : 900 rpm

I'm at a loss here of what to do next and could use some advice. I'm thinking of pulling the engine to do a refresh/rebuild over winter but hate the idea of finding little to no definative damage.

Thanks, Martin

Wed Sep 26, 2012 6:26 pm

I can't offer much advice regarding the flooding other than asking if the second flooding occurance happened when the shutoff valve was closed?

You'll definitely want to readjust your valves, .06mm is only .00236" and you need .006" (.1524mm), hope you haven't had it like that for long.

Wed Sep 26, 2012 6:51 pm

A thought, are you running an electric fuel pump? If so, is it regulated or set at the correct pressure for the carb?

Wed Sep 26, 2012 6:59 pm

Sorry I slipped a zero and UM :oops: valves set at .006 in. The ball valve was'nt installed at that point. I wanted to trust my solution about 2 months.
edited post

Wed Sep 26, 2012 7:20 pm

peaceful warrior wrote: A thought, are you running an electric fuel pump? If so, is it regulated or set at the correct pressure for the carb?

Yes, it is a electric carter rotary pump(3.5 psi max). I wanted to eliminate that factor and added the regulator set at 3 psi.

Wed Sep 26, 2012 9:46 pm

Tough stuff, i went through the exact same situation on my last engine, but with stock dual solex carbs...no carb is immune!

are you still parking on that slope? do you always park int he same direction on that slope? slopes are tricky with carb floats.

i ended up with the valve on the regulator tee as you have, and i parked the bus, closed the valve, and ran the fuel out of the carbs each time i was so paranoid.

could be the dull thud is worn out bearings, they dont last long with heavy fuel in the oil...my old one started the same noises... good news could be that the bearings are so tough they will stand up for a while yet with good oil, so i've been told before.