Hot Engine and Oil light on advice needed

[J4yman]

Sorry for the long post. I have a stock engine with Electronic Ignition and a new fuel pump after a recent failure. New oil and I have checked the oil pressue with a guage. The guage was showing 19lb on idle after driving to the guy who tested it for me which was only 2.5 miles away so the engine was relatively cool. Then 35lbs at 3500 rpm. The engine runs just fine, until the engine gets hot on a run. I went from Coventry to Malvern and I drove about 30 miles to Hopwood Services and stopped as the Save My Bug light started to flicker. So I stopped for 10 minutes and checked the temp on the dipstick with a heat sensor(I know they aren't great but gave me an idea). The temp on the block was 79 degrees and the dipstick was 95 degrees. The light went off and I decided I had to carry on. It was Busfest and I had the family with me. The light was off then came flickering on the M5 again. I was ticking along at 55mph about 3k revs or just over. I decided to raise the revs a little to 3500revs and 60. At which point the flickering stopped and the light went out. Which I thought was odd. Then after a while slowed a little and it came on again. When I got off the motorway the light flickered all the way until I got to Busfest. The engine was running just fine and the temps were about the same as previously mentioned when I arrived. So then there's a definate problem. I have all the tinware in place and the bus runs fine. The journey home was trouble free other than the light was flickering and pretty much more on that flickering when nearly home. But again it ran fine. What I don't want to happen is for it to end up dead quickly. So I am looking for an easy way to fix this or keep it going. I am guessing it's terminal but would like to see if I could get a bit more life out of it as it runs sweet. I have seen mentioned some oil which may help. I am currently running Morris as recommended by VW. But some have said that 20w50 mineral Westway. Another thing would potentially be heavy duty oil pump. Any help or advice would be great. I ultimatley need a recon engine block but can't do that at the minute.

 

[ozziedog]

If you are running Morris straight thirty, this may be your issue. Straight thirty is definitely not recommended by VW. It was recommended by VW back in the dark ages but they changed as the oils changed as technologies changed. This is a very primitive motor and you could run it on lots of different types of oil. You can go to the high zinc content etc etc etc. If it was a racing or high spec motor I can get with the expensive oils, but it isn’t, it’s a slightly worn stock motor that needs more than anything TLC. I use Halfords multi flavour oil especially designed for old bangers and this is more, much more than good enough. The service interval for these air cooled motors was three to five thousand back in the day, but that was when it was new, the motor was new, the wheel bearings were new etc etc. As the motor gets older it needs a tad more cosseting. I change my oil every two to three thousand miles or more if I think of it. Every so often there’s a special on oil s at Halfords and I get a couple of gallons. I keep two separate one litre containers in the van, and one by the back of the van in my garage, I also check my oil before I start the motor and make sure it’s on the the line or thereabouts. Sixty miles an hour is great in a fresh motor but maybe fifty or fifty five with a motor that’s showing signs of wear as in oil use or getting a bit warm is more sensible and add to the longevity of it.

Ozziedog,,,,,,,,,,,, multi flavour,,,,,amaze yourself

 

[ozziedog]

If you are running Morris straight thirty, this may be your issue. Straight thirty is definitely not recommended by VW. It was recommended by VW back in the dark ages but they changed as the oils changed as technologies changed. This is a very primitive motor and you could run it on lots of different types of oil. You can go to the high zinc content etc etc etc. If it was a racing or high spec motor I can get with the expensive oils, but it isn’t, it’s a slightly worn stock motor that needs more than anything TLC. I use Halfords multi flavour oil especially designed for old bangers and this is more, much more than good enough. The service interval for these air cooled motors was three to five thousand back in the day, but that was when it was new, the motor was new, the wheel bearings were new etc etc. As the motor gets older it needs a tad more cosseting. I change my oil every two to three thousand miles or more if I think of it. Every so often there’s a special on oil s at Halfords and I get a couple of gallons. I keep two separate one litre containers in the van, and one by the back of the van in my garage, I also check my oil before I start the motor and make sure it’s on the the line or thereabouts. Sixty miles an hour is great in a fresh motor but maybe fifty or fifty five with a motor that’s showing signs of wear as in oil use or getting a bit warm is more sensible and add to the longevity of it.

Ozziedog,,,,,,,,,,,, multi flavour,,,,,amaze yourself

P.S.
Id stick with mineral oil though.

 

[K@rlos]

First off you need to find out what the oil pressure is doing throughout the Rev range when fully up to temp. If the pressures are good then check the tune of the engine, if it’s running really lean or timing is too far advanced the engine will run hotter and can cause over heating, also be sure the fan belt is correctly adjusted as if that’s slipping at spec. If the pressure isn’t where it should be then you’ll need to dig deeper, could be a simple sticking pressure relief valve or worn oil pump or it could be worn bearings. If it turns out to be a knackered engine then yes a bigger oil pump could be a temporary bandage but you’ll still end up with the same result.

As for oil, SAE 30 is old hat and belongs in lawn mowers VW actually superseded it to multi grade. We only use lucas hot-rod mineral in the engines we do. 20w50 in stock or mildly tuned builds and 10w40 in the more serious stuff like my 2276 nitrous motor. Lucas oil isn’t cheap, £50 I think for 4.5 litres but it’s specifically designed for old engines with flat tappets like aircooled vws & old V8’s so has all the required additives to keep engines healthy but in an engine you plan to ditch in the near future use a cheap 20W50 however if or when you get a new motor use a top quality oil. I personally don’t rate those dip stick things either

 

[Graham L]

Personally I wouldn't trust the save my bug unless it's been calibrated properly, they are notorious for giving false readings as it's a bit of bent copper that sends the signal.
As others have said don't use a monograde, VW changed the spec in the mid 70's and we have always used a 15/40 mineral oil in all of our standard ISH engines, the westway oil is good and we have used that as well as others but it has to be a mineral engine oil to help with cooling and lubrication.
You definitely don't need a heavy duty oil pump on a stock engine, you will end up pushing oil out of every orifice

 

[klotsie]

First off you need to find out what the oil pressure is doing throughout the Rev range when fully up to temp. If the pressures are good then check the tune of the engine, if it’s running really lean or timing is too far advanced the engine will run hotter and can cause over heating, also be sure the fan belt is correctly adjusted as if that’s slipping at spec. If the pressure isn’t where it should be then you’ll need to dig deeper, could be a simple sticking pressure relief valve or worn oil pump or it could be worn bearings. If it turns out to be a knackered engine then yes a bigger oil pump could be a temporary bandage but you’ll still end up with the same result.

As for oil, SAE 30 is old hat and belongs in lawn mowers VW actually superseded it to multi grade. We only use lucas hot-rod mineral in the engines we do. 20w50 in stock or mildly tuned builds and 10w40 in the more serious stuff like my 2276 nitrous motor. Lucas oil isn’t cheap, £50 I think for 4.5 litres but it’s specifically designed for old engines with flat tappets like aircooled vws & old V8’s so has all the required additives to keep engines healthy but in an engine you plan to ditch in the near future use a cheap 20W50 however if or when you get a new motor use a top quality oil. I personally don’t rate those dip stick things either

Why would you wanna have a thinner oil in the more tuned engine?
The racing oil i used to use in a different brand motor was 10W60. Then if it would heat further up, there is still thickness in the oil, so pressure is still remained.

 

[nairb356]

Why would you wanna have a thinner oil in the more tuned engine?
The racing oil i used to use in a different brand motor was 10W60. Then if it would heat further up, there is still thickness in the oil, so pressure is still remained.

I had exact same problem last march
Oil pressure would waver and sometimes drop to zero and light would come on and go off again
(This was with new vdo gauge and sender)
I removed the two pressure relief pistons
Polished them with wet and dry and replaced them - problem sorted!!!
2000 miles since and no reoccurrence
Will polish them at the start of the season from now on
Hope this helps!
Brian

 

[K@rlos]

Why would you wanna have a thinner oil in the more tuned engine?
The racing oil i used to use in a different brand motor was 10W60. Then if it would heat further up, there is still thickness in the oil, so pressure is still remained.

Because they are built to tighter and closer tolerances. 25psi oil pressure @ idle and peaking at 65psi @ 7000rpm while reading 215f oil temp is more than enough. Too much oil pressure is as bad as too little.

 

[james_stan]

It was hot at the weekend - that won't have helped, my oil light was flickering at a (very low) tickover too.

 

[Earlybay1]

Oil recommendations from the Bentley manual stating why mono grades are obsolete

 

[Clem]

Fair enough that oil has changed and a multi grade now >mono grade but, thats not what is causing/caused this.

 

[J4yman]

First off you need to find out what the oil pressure is doing throughout the Rev range when fully up to temp. If the pressures are good then check the tune of the engine, if it’s running really lean or timing is too far advanced the engine will run hotter and can cause over heating, also be sure the fan belt is correctly adjusted as if that’s slipping at spec. If the pressure isn’t where it should be then you’ll need to dig deeper, could be a simple sticking pressure relief valve or worn oil pump or it could be worn bearings. If it turns out to be a knackered engine then yes a bigger oil pump could be a temporary bandage but you’ll still end up with the same result.

As for oil, SAE 30 is old hat and belongs in lawn mowers VW actually superseded it to multi grade. We only use lucas hot-rod mineral in the engines we do. 20w50 in stock or mildly tuned builds and 10w40 in the more serious stuff like my 2276 nitrous motor. Lucas oil isn’t cheap, £50 I think for 4.5 litres but it’s specifically designed for old engines with flat tappets like aircooled vws & old V8’s so has all the required additives to keep engines healthy but in an engine you plan to ditch in the near future use a cheap 20W50 however if or when you get a new motor use a top quality oil. I personally don’t rate those dip stick things either

So the. Here's the oil pressure, 950 lower reading, 2500 rpm second reading and 3000 3pm third reading. Probably not the best oil pressure guage. What I did notice was that the temp on the dipstick was less than the oil pressure guage input. See pics

 

[milfredo]

So 10/40 or 20/50??

 

[K@rlos]

Those pressure readings aren’t terrible! It’s not uncommon for an old stock 1600 to have an idle pressure of 5psi and the oil light to flicker when hot. Those save my bug things aren’t great, I’d take it out and carry on using the bus.

 

[K@rlos]

So 10/40 or 20/50??

Unless you have a high rpm performance engine 20w50

 

[pierrox]

Same. 20W50 is good for our old engines. Thick enough when it's cold so it won't leak everywhere you park, and thick once hot because there's a lot of play in there.

 

[J4yman]

I had exact same problem last march
Oil pressure would waver and sometimes drop to zero and light would come on and go off again
(This was with new vdo gauge and sender)
I removed the two pressure relief pistons
Polished them with wet and dry and replaced them - problem sorted!!!
2000 miles since and no reoccurrence
Will polish them at the start of the season from now on
Hope this helps!
Brian

I think I will do this too when I am changing the oil. Are their specific seals for them?

 

[Earlybay1]

Fair enough that oil has changed and a multi grade now >mono grade but, thats not what is causing/caused this.

that was only to show that the purists have to change their choice of oil. Other causes of overheating and not from a device that is misleading (I would bet is is made somewhere that is renowned for poor quality in all its manufacturing base.) A slipping generator/alternator belt, poorly fitted tin ware including missing plug grommets will reduce air flow. Is the flap stat if fitted opening? A reconditioned engine I bought had the original tinwork fitted and I dug out half a bucket of grime from inside along with the fan. The fan was visibly filthy and caked. That is just incompetence or carelessness . So if you buy something that God knows how many people before you have messed about with do your own checks of everything. I suspect that add on device is U/S as it was stated increasing engine speed caused the light to go out so there is conflict there. 95C sounds ok so another conflict there. If the engine was really overheating you would definitely smell it too and it would be smoking hot!

 

[K@rlos]

I agree, 95c isn’t anything to worry about

that was only to show that the purists have to change their choice of oil. Other causes of overheating and not from a device that is misleading (I would bet is is made somewhere that is renowned for poor quality in all its manufacturing base.) A slipping generator/alternator belt, poorly fitted tin ware including missing plug grommets will reduce air flow. Is the flap stat if fitted opening? A reconditioned engine I bought had the original tinwork fitted and I dug out half a bucket of grime from inside along with the fan. The fan was visibly filthy and caked. That is just incompetence or carelessness . So if you buy something that God knows how many people before you have messed about with do your own checks of everything. I suspect that add on device is U/S as it was stated increasing engine speed caused the light to go out so there is conflict there. 95C sounds ok so another conflict there. If the engine was really overheating you would definitely smell it too and it would be smoking hot!

I agree, 95c is fine. Oil needs to reach that kind of temp in order to get rid of moisture, 115+ + is when you need to worry.

Check the relief plungers, only use regular copper washers I believe. Put some fresh oil in it and also check the oil pick up isn’t loose. That can cause the pump to suck air and pressure will drop.

 

[naskeet]

I used Mobil 1 fully-synthetic, SAE 5W/50, API SF & SG oil in the VW 1600 Type 1 style, AD-Series engine.

Sometime in circa 1985 or 1986, I bought a job-lot of about 20 litres, of heavily-discounted (circa £4•50 or £5•00 instead of circa £12•50 per 4-litre can - approximately 1 US gallon) Mobil 1 SAE 5W/50, API SF or SG fully-synthetic lubricating oil from the local Mobil franchised petrol filling station of Key Markets supermarket, on Canvey Island, Essex, England.

When using conventional mineral oil (SAE 30 monograde or SAE 20/50, 15/50 or 10/40 etc multigrade) in the AD-Series, twin-port, VW 1600 Type 1 Beetle style air-cooled engine, of my family's 1973 VW 1600 Type 2 Westfalia Continental motor-caravan, the oil turned from light-straw colour to virtually black with dark-grey glutinous sludge, after 3,000 miles of use, when the next oil-change was due. The oil-consumption rate was circa 1 litre per 1,000 miles and one often noticed the acrid smell of oxidised oil, when opening the engine-compartment hatch.

However, when Mobil 1, SAE 5W/50, API SF or SG fully-synthetic oil was used, it changed in colour from ultra-light straw to light-straw after 3,000 miles, with NO sludge formation whatsoever. The oil-consumption rate was reduced to circa 1 litre per 3,000 to 4,000 miles and there was no acrid smell of oxidised oil, when opening the engine-compartment hatch.

The 5W viscosity cold-starting characteristic, also made starting much easier in cold weather, but I suspect it led to oil being diverted through the oil-cooler prematurely, owing to the low viscosity at low temperatures.

When starting-up at cold winter temperatures, the VDO Cockpit 0~5 Bar oil-pressure gauge typically indicated circa 3•5~4•0 Bar, but quickly settled down to 3•0 Bar at normal road speeds and 1•0 Bar at idle, which were typical readings at all steady-state running oil-temperatures in both summer & winter.