Beetle Cooling

[Richard]

Well,
I have been having what I think is a cooling problem with my bone stock (as far as I can tell) 1964 1200cc 40 HP engine since the weather warmed up in the spring. After driving 20-30 minutes or at speed on I-295 for an exit or two the oil dip stick is too hot to touch and there is no fuel in the filter (yes, I know the two camps on having a filter in the engine compartment - that will be changed AFTER this problem is solved) and the car hesitates and feels starved for fuel, especially when pulling low in first and second gears.

So... overheating? Fuel delivery problem causing it to run lean? Fuel pump issues when hot?

I installed a new fuel filter and when the engine was cool it filled right up with fuel upon starting the engine. I guess that rules out a clogged line or crud in the tank.

I've read everything I can find and come away with the impression that any number of other problems could be causing this problem.

I did discover something interesting today. It seems that the part of the thermostat system that sticks into the front of the air shroud (looks like an air horn) is missing. I checked with my hand and with a mirror and the sucker is not there. My first thought is that it would help the cooling air flow, but now I'm wondering if that is so. Perhaps it works like a venturi to accelerate the flow of air?

I'm kinda out of my depth here.  :confused04:;

The PO used 10w-30 dino oil. When the engine was hot the pressure light would illuminate at low RPM's. Since changing to 10w-40 semi-synthetic that problem seems to have mostly gone away.

Any help, thoughts, whatever would be much appreciated. If one of you engine guru's want's to see it first hand or drive it I'd be happy to bring it your way.

I was planning to start tearing the car down to freshen it up, but I'd like to get this sorted out before hand. When I get a chance I'm planning to check out the Oil Pressure Relief Valve to make sure that's not stuck down.

I guess that's enough for one post...

Thanks,
Richard

[lovebus (jack)]

The fan shroud has two arms behind it that open the cooling fins. reach behind the shroud and pull the arm towards the right side of the car. when you let go the arm should snap back to the left side. if it dont you are missing a spring that should keep the fins open when no thermostat is not working or not there.

ops, I just saw your thermostat part of your post, disregard the above your must have a 40 HP.

[Bob(Herbie)]

Richard,
What year is your engine? The cooling/thermostat systems varies from year to year. Early 40 hp is different than late 40hp, 1300, 1500 and 1600 single port!  71 up with dual port is different that earlier engines!
15/40 diesel oil gives much better oil pressure and bearing protection. I would not use 10/40 in anything. GM for example said use of any 10/40 oil voids the warranty on their engines! GM had a terrible problem with 10/40 oil breaking down and damaging engines. I researched this and found that there are too many additives in 10/40 oil and not enough oil molecules! Remember when these V-Dubs were new straight 30 weight oil was recommended! Oil has come a long way since then! I use 15/40 in all my V-Dubs. Just my opinion! Good luck!
Bob %$oldcit

[Richard]

Sorry,
I guess the year of my engine is something I should have included.

I've got a 64 Beetle with the original 1200cc 40 HP engine.

It's covered with oil. Seems to be coming from the front main shaft bearing and from "somewhere" else. The entire engine seems to be covered in it. Still, it doesn't seem to consume too much. No smoke from the exhaust. But, I digress....

[6T5 square]

15/40 diesel oil? why? never heard such crazy talk?

Actually I'm trying to figure out what I should be running in the beetle.

[Richard]

You may find these pages interesting:

http://www.mobiloil.com/USA-English/MotorOil/Files/Mobil_1_Product_Guide.pdf

http://blog.hemmings.com/index.php/2012/10/18/tech-101-zinc-in-oil-and-its-effects-on-older-engines/

But... I don't think an oil issue is what's causing my problems.

Took the Beetle for a 40 minute drive today in much cooler temps than the last few days. Also very cloudy. Engine didn't get as hot. I was able to touch the oil dipstick. It was hot, but didn't burn me. Didn't feel like the engine was starving for gas. But.... fuel filter was still virtually empty.

What's going on??? This doesn't seem normal.

[Bob(Herbie)]

Richard,
You may need a new fuel pump mounting block. They some times crack and expand which slows or stops the movement of the fuel pump rod.  %$oldcit

[Bob(Herbie)]

You may find these pages interesting:

http://www.mobiloil.com/USA-English/MotorOil/Files/Mobil_1_Product_Guide.pdf

http://blog.hemmings.com/index.php/2012/10/18/tech-101-zinc-in-oil-and-its-effects-on-older-engines/

But... I don't think an oil issue is what's causing my problems.

Took the Beetle for a 40 minute drive today in much cooler temps than the last few days. Also very cloudy. Engine didn't get as hot. I was able to touch the oil dipstick. It was hot, but didn't burn me. Didn't feel like the engine was starving for gas. But.... fuel filter was still virtually empty.

What's going on??? This doesn't seem normal.

Thanks Richard. Very good information!

[Bob(Herbie)]

15/40 diesel oil? why? never heard such crazy talk?

Actually I'm trying to figure out what I should be running in the beetle.

John,
I follow manufacturer's break-in for camshafts, ad a little STP or Lucas Oil Stabilizer and Gulf 10/40 oil. I tried Diesel oil many years ago and it was the only oil that would stay in my old 36 and 40 hp engines in hot weather! I also ran diesel successfully in an Okrasa engine years ago! ALL I CAN SAY IS IT WORKS FOR ME!  %$oldcit

[Richard]

You may need a new fuel pump mounting block. They some times crack and expand which slows or stops the movement of the fuel pump rod.  %$oldcit

Interesting. I've read about the new re-pops being too tight and causing that problem. I'll check it out. It will give me an excuse to check the filter in the pump also. I'll need to order a couple new gaskets, too. Is there enough movement to leave the fuel line attached, or do I need to undo the fitting? Is there any type of seal within that fitting that I'll need to replace if I disconnect it? Sorry, still learning these strange little engines. Makes the Miata engines I've been working on the last bunch of years seem like sophisticated big blocks!!!

Thanks for all the feedback so far. Much appreciated.

Any thoughts on my missing throttle ring?? Is that helping or hindering cooling?
Just happened to find one on TheSamba yesterday. Included the whole system from throttle ring to bellows and bracket. Sometimes life is good...

[Bob(Herbie)]

The ring was used on 25 hp, 36hp and early 40 hp engines. The purpose is to block air when the engine is cold. This warms the engine to operating temperature sooner than not having the system.
%$oldcit

[Richard]

So then, it has no function in cooling the engine and if I wanted I could strip the entire system? This Beetle will most likely NEVER see winter weather.

I'll be doing a 90% stock driver level restoration. If the above is true, I could just restore the thermostat system and leave it boxed up for any possible future use.

I think I remember seeing or reading about a re-designed plug for the oil pressure relief valve that is machined for a hex wrench but I can't find it now. Anyone familiar with it?

[DWP]

Oil plug
http://vwparts.aircooled.net/Allen-Relief-Spring-Plug-Each-113-115-431-p/113-115-431.htm


DWP

[Richard]

Yup, that's the one.
Thanks!   thumpup)-