Overheating During Highway-Speeds

[KoMbI19]

Hi all-

having a problem with my 73 Super when running it over 60-65 while on the interstate. I never really ran it over 55 before on our country roads out here in Ohio but occasionally if there is a show a little bit aways off it is necessary for me to take this route. But after maybe 15-20 minutes of driving, the temp gauge creeps up to 200, 220, and once 250 before I had to shut her down to cool off. But when driving 55 or below I can usually get 180 constant, and not much more.

All of my cooling tin is in place, and I even have decklid standoffs that ive run for a while, but it still seems to creep up on me when doing 65.

So my question is, what should they run at when at these speeds, and what is something I need to check first?

Stock 1600 DP single carb, in time, new oil cooler (stock style), 10-w-30 Royal Purple synthetic, bolt-on oil filter and larger oil pump gears that came with the CB kit. Gearbox has stock gears, and I have considered getting a taller 4th installed to lower rpms at these speeds. Any help is greatly appreciated.

Thanks! -JD
_________________
1972 Karmann Ghia Coupe- all stock
1982 Rabbit Convertible FI- all original
2006 Chevy Colorado Z71- 215k and still kicking!

[57BLITZ]

[KoMbI19]

I'll check that! I hadn't even thought of that posing an issue, but now the fog is clearing......
_________________
1972 Karmann Ghia Coupe- all stock
1982 Rabbit Convertible FI- all original
2006 Chevy Colorado Z71- 215k and still kicking!

[57BLITZ]

Give your baby a NEW belt to preclude the problem of a hard, stretched fan belt slipping at high RPMs.
_________________
Jesucristo es mi Señor y Salvador!

[Eric&Barb]

Do you have the DH crank pulley and DH cooling fan? The latter came in three widths, of course the biggest was best for cooling.
_________________
In Stereo, Where Available!

[KoMbI19]

http://www.thesamba.com/vw/forum/album_page.php?pic_id=1547653

All looks stock, and I haven't changed either pulleys nor adjusted them since I have owned the car.
_________________
1972 Karmann Ghia Coupe- all stock
1982 Rabbit Convertible FI- all original
2006 Chevy Colorado Z71- 215k and still kicking!

[airschooled]

What temperature are you taking about? Cylinder head temp? Oil temp? Celsius? Fahrenheit? Details matter! Where is your temperature sender located?

Robbie
_________________
Learn how your vintage VW works. And why it doesn't!
One-on-one tech help for your Volkswagen:
www.airschooled.com

[KoMbI19]

oil temp. Not sure on the location, but the gauge seems accurate.
_________________
1972 Karmann Ghia Coupe- all stock
1982 Rabbit Convertible FI- all original
2006 Chevy Colorado Z71- 215k and still kicking!

[ashman40]

You mentioned "in time". I'm guessing that is some reference to the ignition timing being correctly set without actually telling us how you have set the timing? Please provide specific details.....

Carb make/model#
Distributor make/model#
What was your procedure for setting the timing? FYI, timing should be set based on the distributor model you have installed. If the distributor is not the original model that came with the car you should NOT assume you can use the stock timing values. You may need a mirror to see the model numbers stamped into the distributor body. Look those numbers up here:
http://www.oldvolkshome.com/ignition.htm

One tip: If you plan on another freeway trip, I'd suggest you open your engine lid and place a cut tennis ball on your lid latch. This will keep the lid ajar and allow lots of cool air into the engine compartment.
Are you running the stock engine lid with the four sets of louvered slots? These were added in '71 to allow for the greater airflow needed by the 1600DP engines. This was the same year the doghouse fan shroud went to the wider fan for more cooling. More air means more cooling but that air has to come from somewhere, the extra vents in the deck lid is how that extra air gets into the engine compartment.
Overheating is a common problem when installing an earlier deck lid (no louvers) on a later car. Or installing a larger engine in an earlier car.
_________________
AshMan40
---------------------------
'67 Beetle #1 {project car that never made it to the road }
'75 Beetle 1200LS (RHD Japan model) {junked due to frame rot}
'67 Beetle #2 {2019 project car - Wish me luck!}

[RTope13]

check the firewall insulation to make sure the fan isnt pulling it in and restricting airflow

[vamram]

[Zylinderkopf]

Interesting spot for your Royal Purple!

I would check the timing and also check the oil cooler and fan for damage or debris. 200 and even 220 degrees oil temp is actually not so bad. You may want to verify the accuracy of your gauge by using a long stem cooking thermometer as a dipstick.
_________________
1963 Beetle
1966 Beetle 1300
1970 Karmann Ghia Coupe
1971 Super Beetle
1974 Thing


"A lot of people never use their initiative because no one told them to."

[Cusser]

If you have air flaps in your doghouse fan shroud, make sure that they are actually fully open after about 15 minutes of driving.

I'm assuming that your fan shroud is the original 1973 one here, and that the fan inside it is the correct width for that one as well.
_________________
1970 VW (owned since 1972) and 1971 VW Convertible (owned since 1976), second owner of each. The '71 now has the 1835 engine, swapped from the '70. Second owner of each. 1988 Mazda B2200 truck, 1998 Frontier, 2014 Yukon, 2004 Frontier King Cab. All manual transmission except for the Yukon. http://www.thesamba.com/vw/forum/album_page.php?pic_id=335294 http://www.thesamba.com/vw/forum/album_page.php?pic_id=335297

[KoMbI19]

vamram-
I wasn't aware the vacuum lines were incorrect... I recently had the engine out and did a light rebuild (rings, pushrods, tubes, etc.) and hooked it all up as it was. That port/nipple from the intake was actually plugged long before I got the car and was wondering why. I'll hook them up correctly and recheck timing. I set the time according to rpms/ ear because It has a different dizzy that isn't factory installed. If anyone recalls the incident/post from after the rebuild, the wire locations on the cap are totally switched around from what they should be. Also, the markings on the crank pulley don't seem right (as if someone notched some others in there), so it's all a bit of a hash as far as timing goes.

I have a tach and I set it to around 800-900. But after a bit of driving after its hot, it revs more along the 1200 mark at idle. It seems to vary by temp a lot. Not sure on that one. Perhaps it has to do with the wrong vacuum lines.

Also, the doghouse is original to the car, and the fan is also correct. The cooler is brand new with less than 1k on it and as I said, cools fine until highway speeds.

The decklid is also the original for 73, with the four sections of slots. As stated I also run standoffs and thought that they would take the place of the tennis ball trick, but I am open to trying it out.

I haven't checked yet the flaps/t-stat yet, but I probably ought. They seemed to work fine when I put the engine all back together, but maybe something came disconnected or isn't opening fully.
_________________
1972 Karmann Ghia Coupe- all stock
1982 Rabbit Convertible FI- all original
2006 Chevy Colorado Z71- 215k and still kicking!

[KoMbI19]

Oh, and I'm pretty sure the gauge is accurate. When it hit 250, the oil idiot light came on and I immediately shut it down.
_________________
1972 Karmann Ghia Coupe- all stock
1982 Rabbit Convertible FI- all original
2006 Chevy Colorado Z71- 215k and still kicking!

[Tim Donahoe]

I suspect your thermostat isn't adjusted properly and your flaps aren't opening all the way. Adjust per Bently with the engine cold, and check to see that the thermostat bellows opens all the way when the engine is warmed up (the thermostat will fill up all the space in its bracket).

Also, your setup looks like it should be timed to 7.5 degrees BTDC. You may have a pulley with three notches, so time at the proper one.

Check your plugs for lean running.

Tim
_________________
Let's do the Time Warp again!

Richard O'Brien

[KoMbI19]

Just drove around a few blocks and found that the thermostat wasn't opened at all at 180*. So I'll try and adjust it up, drive, and hopefully we've found the problem!
_________________
1972 Karmann Ghia Coupe- all stock
1982 Rabbit Convertible FI- all original
2006 Chevy Colorado Z71- 215k and still kicking!

[Eric&Barb]

Crank pulley looks like right size. Do measure the cooling fan next time you have the engine out to make sure. Measure at outer edge between the two discs that make up the fan.

Get a meat or candy thermometer to double check your oil temp gauge. Look for one with 1" dial to fit down in the limited space and at least a 6" long probe. Check it with boiling water and do adjust for your altitude.
_________________
In Stereo, Where Available!

[hitest]

Do you have a roof rack? I believe they interrupt air flow. If not...

I'd also try it without the stand offs to get a baseline. All mechanical adjustments should vary slightly because of these stand off brackets.

Off that bat- I think you're scooping in more than air your engine's able to pump out.
_________________

[Randy in Maine]