Oil coming up through dipstick at high revs

[iknowdavehouse]

Hi,

I recently had a generator to alternator conversion which involved replacing the stand, oil filler, fuel pump and breather pipe from the filler to the carb. At the same time the main engine seal was replaced along with carb and fuel pump gaskets and pedestal.

I have a 1600 engine with a Weber 32/36 progressive carb.

Since the installation I am getting oil spurt out of the top of the dipstick at high revs. I ran the engine without the dipstick to check and it's definitely coming from there.

The engine is a lot more "sealed" than it was, and my previous breather pipe basically did nothing because it wasn't air tight.

Any suggestions about what I should try?

 

[atafonso]

You probably do not have enough crankcase ventilation from your breather.
Could you show us a pic of your setup? Specially the connection from the breather to the carb.
Abel

 

[iknowdavehouse]

Not at home at the moment but it’s this set up, the connector from the breather pipe into the carb is a right angle and into the bottom of the air filter

 

[iknowdavehouse]

Here’s some extra photos with the join to the carb

 

[atafonso]

Just as i suspected.
The I.D. of the nipple on the breather tube is too small, around 9mm which is even smaller than the early original breather pipe.
Second and most important, the plastic fitting from the carb to the hose is the main problem as the I.D. of that is even smaller.
To make it work well, remove the alu breather tube, tap it for 3/8"npt for a barbed fitting and use a 1/2" I.D. hose. Get one of the 90 deg brass oil fittings used for full flow oil filter conversions and with another 3/8" barbed fitting install on the air cleaner. The 90 deg fitting has a step inside and can be enlarged to 11mm. That should be enough breathing for your 1600
Abel

 

[iknowdavehouse]

Thanks Abel, really appreciate the time.

Since you’ve said this I’ve been able to narrow the issue down and have seen there’s many similar problems with the Weber specifically. I saw a YouTube video where someone actually just drilled a hole in the air filter for a larger pipe to feed into and avoid using the right angled plastic fitting.

Thanks again

 

[atafonso]

That's it, as long as you have at least around 10mm of I.D. on the breather at all parts of the hose, you will be fine
Abel

 

[iknowdavehouse]

Interestingly after buying a new hose, I've now gone back to my setup to put it on and in fact my current hose has an ID of 13mm, so does the right angle connector into the air filter.

Any other ideas?

 

[Tofufi]

Those aftermarket oil fillers are very restrictive compared to stock. Take a look at the stub coming off the filler...

Out of interest, why did you remove the standard oil filler? They're a far better design than that aftermarket one...

 

[ozziedog]

One other thought, do you have a new breather hose as well ? Might be worth a look at the inside of this hose, because if it’s the wrong type of hose, the oil fumes can distort it internally and virtually block it off.

Ozziedog,,,, ,,,, go on then,, ask me how I know :mrgreen:

 

[mike202]

I have a 32/36 progressive carb with an alternator conversion. I still have the original oil filler though. This has the tube that goes down through the tinware as well as the vent upwards which I have fitted to the carb air filter with a pipe. If you say the internal diameter of the vent pipe is 13mm and is not blocked this should be adequate. I don't wish to insult your intelligence, but is the pipe blocked at any point? Is there there too much oil in the engine? Is the dip stick an original one fitting properly?

Also, on a separate note you have the discredited braided fuel pipe from the pump to the carb, with the petrol filter between which is not advised. Apologies if you already new this.

 

[iknowdavehouse]

The alternator conversion was done by a mechanic that specialises in air cooled VWs, not by myself.

I didn’t actually realise I could reuse the original filler with that alternator stand. Either way, I no longer have it.

As far as I can tell the breather hose is the correct spec, the replacement oil breather hose I bought from cool air vw is exactly the same. I’ll double check for blockages / warping asap.

It’s definitely not too full of oil, if anything it’s low on oil at the moment.

Really appreciate the advice...and thanks yes, I know about the braided fuel hoses. They are only about a year old but I’ll swap them out / the position of the filter when I get the chance

 

[Moseley]

You say it’s low on oil - is it burning oil? It could be a sign that the piston rings are worn, and renewing some seals has exacerbated the issue. Compression test would say for sure as it’d be reading low if that is what is causing the oil to be jettisoned from your engine!


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[iknowdavehouse]

It’s actually low on oil due to a different oil leak (cracked fuel pump pedestal) which emptied about 1.5litres over the engine bay...haven’t refilled yet

Also replaced the rear main seal...I’m assuming if I had this problem before the oil was just leaking out of multiple places. Now I’ve limited the oil leaks it’s finding the weakest point...which is now it of the dipstick

 

[iknowdavehouse]

And yes the pedestal has been replaced

 

[atafonso]

The hose I.D. can be 13mm but it can be seen that the nipple and the connector actually looks of a smaller diameter. Please correct me if i am wrong.
The nipple of those aftermarket aluminium breather tubes do not have the adequate I.D. as they come from the suppliers.
Abel

 

[Tofufi]

And yes the pedestal has been replaced

The pedestal is different between alternator and dynamo, so your mechanic was probably right to change it. However, I'd go back and ask if they still have the original filler.

In future, think twice about throwing away original parts - in general they're better quality and function better than much of the shiny tat you can buy these days

 

[Moseley]

It’s actually low on oil due to a different oil leak (cracked fuel pump pedestal) which emptied about 1.5litres over the engine bay...haven’t refilled yet

Also replaced the rear main seal...I’m assuming if I had this problem before the oil was just leaking out of multiple places. Now I’ve limited the oil leaks it’s finding the weakest point...which is now it of the dipstick

Fair enough, but given you can’t be sure of why the oil is being thrown out the dipstick, a compression test is a free way of understanding if the issue is internal.


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[iknowdavehouse]

So, I swapped out the hose, removed the right angle plastic joint from the Weber. Drilled though the air filter and put a 1/2inch brass barbed fitting in there...

Just been out on a 30 min dual carriageway run and no oil!!!!!

Thanks again Abel, basically what you said to do all along

Cheers for all of the other advice, I’m going to keep an eye on it!

 

[atafonso]

I am happy that you got it right
Abel