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I have a 1600sp engine.problem is after a short run the oil light starts to flicker then permanently stays on.after which the fuel pump fails at times.I have practically tried almost everything.. replaced the fuel pump,replaced the oil pump, checked the timing,checked the jetting but the symptoms still persist ...the only gremlin left which I suspect is the oil cooler....what do you think guys n gals..could I have a failing/faulty oil cooler?could it be the culprit? what are the signs of a bad oil cooler?

thanks.

monkslayer wrote:I have a 1600sp engine.problem is after a short run the oil light starts to flicker then permanently stays on.after which the fuel pump fails at times.

What weight of oil do you use and what is the outside temperature?

Check the valve adjustment, timing, and adjust the carb and idle speed.
The filter at the bottom of the fuel tank might be clogged up.

Replace the oil pressure switch or install an oil pressure gauge.

This is what I have in mine:
http://vwparts.aircooled.net/VDO-80psi- ... 360009.htm
and
http://vwparts.aircooled.net/VDO-80psi- ... 350040.htm
And
http://www2.cip1.com/ProductDetails.asp ... D14%2D1003

You said the fuel pump fails.
Test the fuel pump pressure.
For a 1600 cc the pressure should be between 3 to 5 psi.

Sometimes the bakelight flange that holds the push rod will get hot and will expand. When it does it keeps the push rod from going up and down.

This causes vapour lock type symptoms
It will start working again once the engine has cooled down.

This is discussed in one of the Bug Me videos I can’t remember which. It was either in the Routine Maintenance or more likely in the Engine Overhaul video.

When you install the flange make sure it goes in the hole easily.
If it takes effort to get it into the hole it might heat up and cause that binding of the push rod.
This is remedied by sanding down the outside of the bakelight flange where it sticks into the hole a little at a time until it goes into the hole easily.
Use air to clean it or rinse and dry it off before putting it in the hole.

Always put the flange in first and then the push rod. Never put the push rod in the flange and try to insert them both in the hole.

Be careful not to let the push rod fall down into the hole.

http://www.vw-resource.com/fuel_pump.html

http://www.vw-resource.com/vapor_lock.html

http://www.vw-resource.com/

I was using 20w50 havoline after which I switched to shell 15w40 which is what I now use. I have done all that,valve adjustment.,timing, Carb adjustment,changed the oil switch, symptoms are still the same.out side temperature is about 28c.

that's why I asked about the oil cooler. any ideas?

It'd be worth taking a look at the cooler. Singleport coolers have been known to "balloon" when exposed to excessive pressure (as might be encountered when revving up a cold load of 20W-50 with a singl-relief case) - the tubes can expand, closing off airflow between them.
It's also possible that the wrong seals were fitted and they're constricting the oil flow. There are two styles of SP cooler, seal selection depends upon which you have and whether the case is small- or large-passage.

http://www.shoptalkforums.com/viewtopic ... &p=1091078

monkslayer wrote:I was using 20w50 havoline after which I switched to shell 15w40 which is what I now use. I have done all that,valve adjustment.,timing, Carb adjustment,changed the oil switch, symptoms are still the same.out side temperature is about 28c.

that's why I asked about the oil cooler. any ideas?

My calculator says 28C = 82.4 F

For 85F/29.4C and under I would recommend a 10W 30 like
Valvoline Racing VV205 Valvoline VR1 Racing Oil JEGS
10W-30.
http://www.ebay.com/itm/Valvoline-Racin ... 2eb897ed06

It has the zinc/ZDDP additive needed for engines with solid lifters like aircooled VWs.

Do you live in the Northern or Southern hemisphere?

Jim Ed wrote:

monkslayer wrote:I was using 20w50 havoline after which I switched to shell 15w40 which is what I now use. I have done all that,valve adjustment.,timing, Carb adjustment,changed the oil switch, symptoms are still the same.out side temperature is about 28c.

that's why I asked about the oil cooler. any ideas?

My calculator says 28C = 82.4 F

For 85F/29.4C and under I would recommend a 10W 30 like
Valvoline Racing VV205 Valvoline VR1 Racing Oil JEGS
10W-30.
http://www.ebay.com/itm/Valvoline-Racin ... 2eb897ed06

It has the zinc/ZDDP additive needed for engines with solid lifters like aircooled VWs.

Do you live in the Northern or Southern hemisphere?

Once I was using 15W 40 and it was about 40F one morning.
The cold thick oil caused my oil cooler to burst.

I don't know if your case is single relief or dual relief but, your oil pressure relief valve and/or your oil pressure control valve could be sticking or be stuck.

actually I live all the way in east Africa, Kenya ..to be precise. it can get pretty hot at times.well let me try a different oil cooler ...will keep you posted.thanks guys.

Update..so after tinkering with the oil cooler(not the problem after all...)..i decided to change the oil pump.What a difference it has made..the car even feels more responsive...smoother on the uptake.I suspect the old pump in the car was weak and kept the pressure way too low.The light still flickers/comes on after a long hard run but goes out after a minute or so.I guess i need to change the oil...maybe i will go back to the 20w50 i used to use.The light never came on when using that weight.Otherwise thanks guys

monkslayer wrote:.The light still flickers/comes on after a long hard run but goes out after a minute or so.

This means you are overheating the engine. The problem is not oil related. It is your whole cooling system or your engine.

monkslayer wrote:...maybe i will go back to the 20w50 i used to use.The light never came on when using that weight.

Unless your engine is high mileage and worn out, using that tar will only mask the problem. You will still have an overheating engine, you just won't know it.

Bruce is right on it, I'm afraid. If that oil light comes on after a run, you're overheating. How old is the engine? Can you feel endplay at the crank? Is the compression good on all 4 cylinders? Do the valve settings change between resets? Does it use oil quicker than 3000 mile changes?

I'm thinking you need to keep going here or you're in danger of a dropped valve or an engine lockup. Much better to catch ahead of that, no matter the hassle.

doc

monkslayer wrote:Update..so after tinkering with the oil cooler(not the problem after all...)..i decided to change the oil pump.What a difference it has made..the car even feels more responsive...smoother on the uptake.I suspect the old pump in the car was weak and kept the pressure way too low.The light still flickers/comes on after a long hard run but goes out after a minute or so.I guess i need to change the oil...maybe i will go back to the 20w50 i used to use.The light never came on when using that weight.Otherwise thanks guys

Why would you change the pump without changing the oil? That makes me wonder if you ever cleaned the screen.

You need to post some pictures of your engine. We may be able to identify things causing your overheating.

Bruce,

calling a 20w50 oil "tar" makes me wonder what you know about multigrade oils (not critising, just wondering). Expressions like 'tar' are likely to frighten those who have little knowledge about oils.

A 20w50 acts like a 20 when it's cold (thin enough to help when starting) and it acts like a 50 when it's hot (thins out less than a straight 30 for example). BUT....a hot 50 oil is still way thinner than a cold 30 and the bugs originally recommended a straight 30 in warm climates, so a 20w50 is NOT NOT NOT "tar". It simply means that it starts out a little thinner than a straight 30 when cold, but it stays a little thicker than a straight 30 when it's hot.

There is an oil viscosity chart on my site if you want to look at the way multigrades work in comaprison to single weight oils.

Also note that once multigrades started getting reliable in the mid 70s the VW Onwer's Manuals started recommending them.

I've been using 20w50 in my bug for over 30 years (I bought the car new in 1970 and it still has the original engine, and I do all the work on it) and it has over 400,000km on it, so please don't say 20w50 is no good for VW engines.

A survey was done on this site about 10 years ago about "what oil do you use", and about 50% of the respondents (and there were plenty of respondents) used Castrol GTX, which was then a 20w50, and quite a few others reported using other 20w50s, and in colder climates 10w30 was popular. And of course some preferred straight weight oils, which is OK if you don't mind changing it for the weather as well as each 3000miles.

Your blind faithfulness in 20W-50 makes me wonder what you know about multigrade oils.

Commonly available oils range from 0W-20 at one end, to 20W-50 at the other end. Why do you use the thickest tar out there? What do you fear would happen if you used an oil in the middle of the range?

Do you have an oil temp gauge?

I will post pics of the engine as soon as I can...the oil light flickers because the idling was way down.I will def change the oil.will offer more updates soon.

I don't have an oil temp gauge.