I have problems with 1600 dubble port Superbeetle. During normal driving
with 60-65 mph on the highway I get an oiltemerature of 120 degrees
Celsius and rising if don't slow down.
I had ignition, carb. values etc. dubble checked but hadn't find any
After a planned partial revison, with new cylinders,piston, heads, Bocar
carb and a rebuild dizzy I have still the same problem, in the
beginning a bit more cause of breaking in the new pistons.
After the rebuild the car has less power (seems to me) and is still
overheating. I checked the ramva archives and triple checked the dizzy,
seems that the vaccumbox is not giving the same amount of advance as the
old one. This can be a cause for the loss of power.
Is it possible that the fuelpump can't deliver enough at highway speeds?
Checking the fuel level in the carb is according to the specs.
I think this is a nifty one as all the 'standard' causes are triple
checked. Possible a sum of more minor malfunctions.
Or a big stupidity by me;-)
Here a list checkpoints done.
TDC mark on pulley is ok
Igniton timing is 7,5 degrees BTDC with vaccumhose disconnected
Dwell angle is 47 degrees
Idlemixture is set to approx. 3,5% CO
Idlespeed is 900 rpm
The thermostat and cooling controle is triple check with the engine out
and in the car. It opens complete.
All airguides and plate are complete and assembled.
Fanbelt tension is correct.
Ok, somebody ready for the challenge?
All suggestions are welcome,
I get the same in my Super Beetle. Though, temp gets up to 260F (no clue
what that is in C) for about 30 minutes of highway cruising. Mine was
timing too far advanced caused by my dist settings. I backed the peak
advance off some, but need to re-check and verify.
IMHO, all bugs need an external oil cooler to help when those little
under-designed engines can't cope.
Would you consider the following engine not to be stock?
1600cc dual port
heads not modified and not using ratio rockers.
cam is stock
Weber DFEV progressive carb with the heated manifold (redline K1410 kit)
dual quietpac exhaust on merged headers
mallory unilite (#48) distributor with MSD 6A cdi ignition box, blaster2
coil and gapped to "0.050
Given that the items are external, I claim it as stock.
You've managed to miss the point.
Normally, only about 15% of the engine's waste heat will appear in the oil. If
the engine is fitted with the dog-house type oil cooler and all other cooling
system components are in place and functional, the oil cooling system provides
about 120% of worse-case capacity.
The point you've missed is that elevated oil temperatures are a symptom rather
than a problem. Normally, elevated oil temperature simply means the engine is
being operated outside of its designed envelope -- the load is too heavy for
the speed or the speed is too high for the ambient air temp, or both. And yes,
on a hot day this can occur with just you on-board. The cure is to simply take
your foot out. Alas, on a southern California freeway that can earn you a
ticket for obstructing traffic, which is why a lot of VW bus owners have
learned to fly by night :-)
The root problem is whatever is causing those elevated oil temperatures -- and
that could be anything from low tire pressure to a loose nut on the steering
Ever had the measles? Your body temp can hit 105. Dunking you in ice water is
a sure-fire treatment of the symptom -- it will bring your temperature down.
(Of course, the shock usually killed the patient :-)
Audit your cooling system. Every part is critical. Check to see that the
deflector plate is installed on the underside of the HEADS. If running
after-market dual-port tin the odds are the gull-wing deflector above the
manifold hole is missing. Check your spark plug seals -- ANY loss of air
PRESSURE guarantees a loss of air FLOW.
Check your fan belt. And the diameter of your pulley. (Those wunnerful 'power
pulleys' guarantee the engine will run hot.) Reach around behind the blower
housing and feel every blade in the fan to insure you haven't picked up leaves
or other debris.
Check your oil pressure. Elevated oil temp is one symptom of a worn-out oil
Check your brakes, tire pressure and alignment. Low tires, draggy brakes and
improper alignment all demand more work from the engine. The car may be doing
65 but the engine could be doing 90.
Ditto for the clutch & tranny. When was the last time you replaced your tranny
lube? (Recommended inerval is 2 yrs or 24,000 miles.)
What kind of shape is your engine in? Yeah, I know -- perfect :-) But a lot
of 'perfect' engines show up here at the shop with complaints of over-heating.
It's not uncommon to find excessive blow-by, indicating worn rings or valves.
And excessive blow-by dumps a huge amount of excess heat into the oil.
After-market carbs are one the main reasons for accelerated wear of pistons &
valves, mostly because of their inadeqaute air cleaners. It only takes about a
teaspoon of dust to trash an engine and anyone who has cleaned an oil-bath air
filter knows the engine sucks in ten times that much between oil changes. The
other failing of after-market carbs is running too rich a mixture, either
because of inadequate manifold heating or running a mechanical advance
Don't take my word for any of this. Conventional Wisdom, as espoused by the
magazines and after-market retailers say that if your oil is running hot you
gotta spend some more money by adding one of their sooper-geewhiz oil coolers,
with a fan yet, and mebbe one of those ohsokewl thermostatic valves that are
guaranteed to leak. And lotsa hose. And fittings. And brackets. And other
Now the oil stays so cool it's kewl. Of course, the root problem -- whatever
it is -- is still there, ticking like a time bomb. And when it goes off those
wunnerful folks will have some more really kewl fixes you can buy. In fact,
the experts have an answer for everything! The only question is, can you
Hot oil is a SYMPTOM. The solution is to deal with the problem that produced
that symptom. Adding an oil cooler is like trying to cure cancer with aspirin.
Also,very important, check the engine to car rubber seal. If this is dried
out,cracked or missing, your engine will suck up the hot air from the muffler
and recycle it and cause a vicious cycle of overheating. Had that problem with
my 67 . Fred67bug
No, awful! Long story short, one of the main bearings on the crank is
shot. At best, she'll get 25psi of oil pressure at highway speed when
warmed-up. About 5psi or less at a stop light. But when cold, she'll get
The replacement engine is almost finished and I'll be swapping to it in a
couple weeks after the new tranny is ready and numerous other tid-bits are
I know I have a pressure problem, but didn't think elevated oil temp would
be a side-effect. I feel sufficiently humbled.
On 13 May 2004 09:22:08 GMT, email@example.com (Veeduber) scribbled
this interesting note:
Granted, your experience is far greater then mine, but what I've found
is that most air-cooled VW engines are filthy on their exterior. And I
mean all their exterior. From inside the fan shroud to the fins on the
oil cooler to the cooling fins on the heads and cylinders to the
grease and oil and road filth covered transmission and engine sump
The last engine I gave a once over to was so dirty that virtually all
the cooling surfaces which are designed to keep things cool were so
clogged up that almost no air was getting to them at all. The engine
ran hot all the time. The oil, even when fresh, would thin out so much
the oil pressure light would come on at idle. After I spent nearly a
week's worth of spare (and not so spare!:~) time taking the silly
thing apart and cleaning it up and putting it back together it ran
nice and cool and is still going strong today. And this was a 36hp
(Remove the Primes before e-mailing me)
Dear John (and the Group),
A friend recently asked me to look at the air-cooled engine on a paving machine
(!). I don't know anything about paving machines. Nor those nifty
two-cylinder Honda engines. But he'd gone through two engines in two years and
it was pretty obvious the Honda guy just wanted to keep selling him new engines
at about two grand a pop.
The engine's fins were covered with fur.
Or what looked like fur. It was dust, glued to the aluminum fins with
Actually, it didn't look all that bad... you could brush it off, which they did
to the inlet grill every morning. But it would come right back because there
was lots of oily vapor getting sucked in by the cooling fan and the machine
spends it's life in a dusty environment.
It reminded me of a 40 horse with a leaky oil cooler -- the famous Volkswagen
The really funny part was the reaction when I pointed out the layer of dust
(which makes a dandy insulator). My friend doubted that such a thin layer of
crud could be enough to over-heat the engine. But it was easy enough to rig a
duct to insure it sucked in only outside air... and without the oily vapor, the
aluminum fins stayed clean... and the thing didn't overheat. (Truth is, I
think the thing originally came with such a duct... that someone had removed to
make it easier to get at the hydrualics.)
Liv & lurn -)
PS -- My personal favorite was the doctor's Porsche and the engine filled with
leaves from a Chinese Elm that shaded his reserved parking space. Even when
you showed him the cylinders packed solid with leaves he kept insisting they
would blow right on through; that SOMEONE must of packed them in there on
purpose. Makes you wonder about his diagnostic skills, eh? :-)
I absolutly agree that hot oil is the symptom not the problem. I have
aftermarket tin upper cylinder covers, the rest is original. What do
mean with the gullwing tins? The tin at the rear (pulley) side which
deflects the air streaming over the upper side of the cylinders to
underside and around the rear exhaust mainfold?
I'm busy at moment to reproduce the small tins for underside of heads,
the where missing on the old heads too. But think this will not gain
more than 5 C (41 F), please correct me if I'm wrong.
The rubber engine seal is also new and fits tight arounf the engine.
As far as remember the tin has no exessive gaps. but I will dubblecheck
in the weekend.
I also will try to put some strap, piece of wood, whatsoever over the
enginebay insulation. I looks solid and fixed to me, but if the possible
is right check the impossible.
As for the engine as stated earlier, it's partial rebuild. All oil
channel are cleaned, everything is clean, new cyl./ pistons and new
heads. The fan pulley is stock as everything else.
As for the carb, it's an out of the box new Bocar 34-3. Only adjusted
idle mixture and speed. All other screws are still seal to get a
reference. The manifold heating is working well and also cleaned. Tire
pressure and brakes move freely. Tranny maybe needs to be change, have
the car just one year and didn't know what PO did.
The Oil pressure is above 65 psi when cold, 56 psi when the oil is 115 C
/ 239 F at 3500 rpm and 21 psi at idle. When the oil get above 120 C /
248 F the pressure drops to 46 psi at 3500 and 6,5 psi at idle, which is
about where the warning light starts.
So I'm still looking malfunctioning. In the weekend I will get another
dizzy and fuelpump.
As I wrote, it's a real challenge.
Look inside the stock DP cylinder-head tin-ware. There is a gull-wing shaped
deflector that directs the blower's output toward the exhaust valves.
Making sure the deflector is a fairly tight fit against the fins immediately
adjacent to the two upper-middle studs is a standard procedure when mantling a
DP engine. Without a well fitted deflector the cut-out for the DP manifold
end-castings is little more than a hole through which your cooling air can
Your OP readings look okay. As a test, change to straight 30W and compare the
results. No difference is good, anything else is a clue that needs to be
It would probably be a good idea to rig some instruments to check the
stoichemistry of your mixture. Same for your ignition timing and compression
ratio. The fact an engine runs does not mean it is running well.
There IS a reason for this sort of thing. Odds are, it will turn out to be
something you've assumed to be okay... and therefore did not check.
finaly check the complete tinwork. No gaps, head deflector tins made and
mounted. Engine runs fine can't find any error in the adjustments.
Called a local Bug specialist who also rebuilds engines and has a quite
good name in tuning. According to him the temperature is quite normal
for a 1600 DP.
So I just continue breaking in and try to enjoy it.
Thanks a lot for all advice. If I find anything else regarding this
topic, I will let you know.
Your engine is a SYSTEM. All of its parts interact. Problems seldom have a
specific single cause but are the accretion of numerous small problems, usually
things deemed unimportant by the 'experts.'
The deflector plates on the underside of the heads serve to maintain adequate
air pressure in the plenum space ABOVE the heads; the gull-wing deflectors
direct the air to where it is needed most; the thermostatically controlled
flaps are designed to align with the central fin on the cylinder head so that
the densest slug of air from the blower is directed to the hottest parts of the
heads... all 'unimportant' details. The failure of any one of them may go
unnoticed until you get a really hot day, or climbing a grade with a heavy
load. Then you will have more waste heat than the engine can managed.
You're looking for a smoking gun -- a single cause of all your problems. Odds
are, you aren't going to find it. What you ARE finding are a host of small
'unimportant' problems, the COMBINATION of which have lead to an episode of
overheating. Now the camel has his nose inside the tent because excessive heat
carries a legacy of future problems; it's a genie that can't be stuffed back in
Most people simply do not believe that such close attention to detail is
NECESSARY. Indeed, the archives of this Group contain dozens of messages from
idiots saying exactly that when someone having more experience tries to explain
why their failure to devote any attention to those 'unimportant' details is the
reason thier ride is a piece of shit.
"All my buds say..."
"I've driven for ten years without..."
"NOBODY does it that way!"
The good dope is in the manuals. The distillation of thousands of man-years
of engineering excellence backed up by more than twenty million engine's-worth
of experience. Build a few engines yourself and perhaps you can ADD TO that
sum-store of knowledge but most of what you read & hear about Volkswagens is
from an idiot with one engine's-worth of experience expressing his expert
opinion, or an after-market retailer preying upon your ignorance.
On Wed, 12 May 2004 21:33:36 -0700, David Gravereaux
actually yes i would consider that stock...go out on a limb and call
it "mildly upgraded" if you wish...BUT if your engine *needs* an
external oil cooler to keep the oil temps down you are looking in the
wrong direction....the stock cooling system can an does keep much
larger high performance engines running nice and cool...the usual
culpirt when trying to chase down overheating problems(whether it be
high head temps or high oil temps(which go hand in hand) ) is usually
missing or poorly fit engine cooling tin...next on the list is
aftermarket tin that usually fits poorly....over advanced timing and
poorly adjusted fuel/air mixture are the next things on the
list.....engine compartment seal is next....and so on and so on....a
properly installed *factory* cooling system is sufficient for 90% of
the engines out there on the street(stock and hi-po both)..
On Wed, 12 May 2004 21:33:36 -0700, David Gravereaux
So if you also bolted on an external supercharger and added nitrous
oxide to the mix (also external) you'd claim it was stock? I need to
bring you with me the next time I go to get my Jeep inspected so you
can talk to the inspectors for me when they start asking questions.
Johnnie Cochran, move over! :-)
It is most definitely NON stock, sorry.
You have altered the breathing of the engine in order to get more power
(or maybe better fuel economy, or whatever). A major change has been
done to the engine, the way it works and breathes.
A stock engine is an angine that still has the same (or equivalent
replacements) parts it had when it left the factory. If you replaced the
31Pict carb with a 34Pict, it no longer is a stock engine. It's
"otherwise stock, except for the carburator".
Saying it's a stock engine will lead to misconception and
misunderstandings. In situations like, when you ask for advice on how to
adjust the carb and/or ignition on your "stock" 1600cc dual port engine.
Any advice you'd get based on that info alone, would be WRONG.
What colour are the spark plugs? If they're very pale and lean looking you
might try going up a size on your main jet. Also, check your wheels drums
aren't binding, sometimes the hoses collapse. Use a good quality 20/50 oil.
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