Vanagon EuroVan
Previous messageNext messagePrevious in topicNext in topicPrevious by same authorNext by same authorPrevious page (July 1996)Back to main VANAGON pageJoin or leave VANAGON (or change settings)ReplyPost a new messageSearchProportional fontNon-proportional font
Date:         Tue, 16 Jul 1996 14:25:34 -0400
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         SyncroHead@aol.com
Subject:      Re: Wasserboxer cooling (was:Re: aftermarket instrumentation)

In a message dated 96-07-16 04:42:03 EDT, jwakefield@4dmg.net (john wakefield) writes:

>Jim Davis wrote (in quotes): >> "BTW do you own one of these motors and have first hand experience with it?"

>I've owned two spark ignition versions and currently own three of the diesel versions.

I'm speaking specifically of the watercooled flat-four engines used by VW in the 1983-1/2 to 1991 Vanaagons. They did not make any diesel wasserboxers. I have not intended any of my comments to apply to diesel engined vans - I have no experience with them. The engines are SO different that I would not presume that any experience with one could be applied to the other.

Have you owned any wasserboxer equipped Vanagons? What years?

>> "I don't recall any cooling problems on the list that were tracked to >>"design flaw". If it were a design flaw, it would be showing itself in >>my vehicle as well - it is not."

>Safety margin required to accomodate >slightly out of spec systems may not be required on yours, and your >experience may simply be a testimony to you and your atypical vigilance >rather than to the bus cooling system design.

I don't do anything vigilant with my cooling system. I just change the coolant every two years. My system is competely stock.

>What differences did VW include in later systems like your 87 Syncro compared to >those before?

Along with the larger engine (same heads I'm told) they changed condsiderably the cooling house routings. I believe this change made it easier to bleed the air from the system while changing the coolant and less likely to leave air trapped in the system.

>> "These are all problems that can and do affect all water cooled >>engines. . . Can you site any examples to the contrary?" >>Yes, I think any comparison with the great mass of alternative brand >>vehicles would easily reveal that water cooled Vanagons have a >>disproportionately larger share of heat related problems than others. Do >>you honestly think that if this were a Toyota or Honda list that engine >>heat concerns would receive much attention? I don't. VW bus failure to >>comply with contemporary world standards in this specific area is >>reflected in that difference.

Yes. I think if there were a forum to discuss problems related to 5 to 13 year old Hondas and Toyotas, there would be a reasonable ammount of time spent on this subject. Also, befor you started bringing the subject up on this list a couple of times a week, there was considerably less discussion of cooling on this list. Much of what there was related to air cooled engines.

>Already two respondents to your note >indicated that they had to stop and let their systems cool during cross >country mountain climbing. Besides antiques and design defects, what >other class of vehicles typically stopped on those inclines? By >contempary standards, if a typical driver has to nurse-maid their VW bus >along while watching to make sure the heat rejection system doesn't get >beyond prudent temperatures, that's a clear indication that something's >different form the norm.

Perhaps they had a specific and repaiable problem with their engines or cooling systems. Also, they indicated that they choose to do this, not necessarily that they "had to" by coolant boiling over or other such needs to stop. These two instances are surely contridicted by tens of thousands of cross-country trips that Wasserboxer owners have made without incident. Personally I have made 8 2,700 mile (round trip) and countless 600-800 mile trips without incident in my 87 and 88 vans.

Mark wrote of his trip in the Rockies "However, with sustained climbing in a lower gear, especially 2nd, temp would quickly shoot up to 230 at which point I would pull over and give her a rest."

Mark owns an 87 Syncro Camper. I think that his example shows about the most extreme case. High altitudes, steep grades, 2nd gear speeds, added weight of Syncro, added weight of Camper, probably added weight of passengers & luggage. I don't know if any other 9 year old (likely considerably over 100k miles) vehicle could be expected to perform much better under such conditions. An example like this of extreme conditions does not prove the point for the general case. Only that when pushed too far, any engine (especially a 9 year old one) will show that it has limits.

Shawn said of his 88 Westy: "While I agree the w/b cooling system seems adequate so far on my '88 under normal conditions, I do find it cannot cope with 1st & 2nd gear travel for prolonged periods, even when keeping revs up to maintain coolant flow. I often stop too cool off after 20-30 minutes of rough road travel in these conditions."

Again, "1st & 2nd gear travel for prolonged periods" is pretty severe duty. However my 87 seems to handle it well enough when I off-road in the mountains & deserts here in California.

But then James Cohen writes: "I have found the cooling to be adequate on all the WB's that I have driven under all conditions UNLESS there was a problem with the cooling system (an all too frequent occurance)."

Indicating that if there's something broken with the cooling system, fix it and the machine will work fine.

>Then you cite your recent personal experience with your fine running >machine. I'm glad that you have your machine running so well. You say >>"I expect that you'll say - "Ahhh, that's only coolant temperature." >No, as a matter of fact, your experience described with your machine >sounds like what all Toyota or Mazda van owners probably expect. I think >if your experience were shared by almost all other owners of VW water >cooled buses, just as with the other brands, this thread would not exist. >Instead, I'll bet there are lots of water cooled Vanagon and Westie >owners on this list whose machines couldn't perform as you described >yours doing.

I think that most of them are performing fine and the ones that aren't are the only ones that we hear about. I think that normal cooling & running Vanagons are the norm here. If it weren't we'd be reading messages like "I made a 100 mile trip today - and I did NOT have to stop to let the van cool down. Can you believe it?" We never hear this because this is the norm. We only read about it on the list when someone has a problem with their system.

>>Jim said >>"While it would be a bad idea to measure coolant temperature >>at the radiator for instrumentation purposes, turning on & off the >>radiator fans with a temperature switch here works just as well as a >>switch at the engine." >Really! So the '83 diesel Westie imprudently >left idling in the hot sun for 20 minutes which never alerted me to the >fact that it was heating by turning on either the low or high speed fan >circuit, but which on returning to the driver's seat was found to have >the heat meter at full scale and the light flashing must have had >defective radiatior mounted fan control thermostat switches, right? >Wrong, I tested both and reported the test a while back in Boiling >Aligators in Florida (having used aligator clip test leads in the water >on the stove). The water in the radiator never got hot enough to call >for the low temp switch to come on at 200 to 208 degrees F. specified in >Bentley. An RV at a camp site should be able to set their idle high to >execute a parked recharge to its battery or batteries, and with an idling >fuel consumption of .13 gallon per hour, the 1.6 VW diesel Westie should >be particularly ideally suited for this. At a pint an hour, that's a >pretty trivial heat load, yet it can't handle it. If you call this >failure to even switch on the low speed radiator fan circuit adequate >design, then I'll accept that you and I have different standards and let >it go at that. Yes it's been front elevated and properly burped.

I don't have an explaination for this. You are right to expect to be able to idle your diesel for 20 minutes without overheating. Perhaps a dying waterpump? A stuck closed thermostat? Loose connections at fan switches or at the fan? I don't know enough about the diesel and it's cooling system to say that this experience can (or cannot) be translated to apply to the wasserboxer equipped vans. My experience has been with the wasserboxer Vanagons, specifically the 2.1 liter version.

I don't know enough about the diesel's system or your incident to call it a case of inadequate design. With the temperature high enough at the engine to cause full scale temperature reading, if the water was flowing, it's hard to believe that the temperature could drop enough in 12 feet to be below the temperature switch's setpoint. If the coolant was flowing, and the switch did not engage, I'd concede that design is a potential problem here. It's hard to determine if the switch engaged though, there could have been a poor connection in the wiring allowing the switch to engage without bringing on the fan. It's also hard to determine if the thermostat was temporarily stuck closed and coolant was not reaching the radiator. Perhaps a design flaw in the thermostat design or in the wiring terminations used?

<SNIP on stuff about diesel used as RV generator>

>> "All VW needed to do is determine the proper engine coolant operating >>temperature, and choose a radiator mounted switch with an appropriately >>lower setpoint to account for the temperature loss in the hoses between >>the engine and the radiator. I believe that they have done this,"

>Again we disagree. I'd agree if the water pump/coolant system flow curve >over the motor's operating range maintained a narrow range between the >block temperature and the radiator, but that's just wishful thinking.

Do you have the coolant pump's flow curve? Have you taken measurements to determine what the temperature variences are? This would be great data. I'd love to see them.

>> "By what calculations have you determined that the coolant lines are >>"undersized - for - their - length" ?"

>Direct observation of differences obviates the need for calculations.

Oh, VW just should have "looked" at them & it would have become obvious to them. Again, I've "looked" at it and I'd speculate that the VAST majority of flow restriction in in the radiator - like every other car.

>Just as with the famous story about >one of Edison's hired engineeers who he discovered deep in calculations >to determine the volume of a flask, Edison took the flask and filled it >with fluid from a calibrated cylinder and made a direct observation. >Similarly, the diesel Rabbit running the same motor but having short >lines performs very differently when idling or pulling an outrageous >load. Same motor, the only reasonably explicable difference is the >different cooling system.

>I'm not going to accept your invitation to engage in personal >comparisons, but in my defence, you described yourself as a kid around >the early 70's when I was working on my post graduate degrees. Could we >stay on the topic of how to make all water cooled VW busses handle heat >as well as yours?

I think that your background and qualifications are an issue here, if you're going to make statement of "design flaw" and being able to assign VW a grade in applied thermodynamics. I'd speculate that you were working on post graduate degrees in literature, not engineering. I don't intend to get personal here, but everyone's statements must, to some extent, be weighed with their speaker's experience & training.

Regards, Jim Davis 87 GL Syncro 88 GL Wolfsburg


Back to: Top of message | Previous page | Main VANAGON page

Please note - During the past 17 years of operation, several gigabytes of Vanagon mail messages have been archived. Searching the entire collection will take up to five minutes to complete. Please be patient!


Return to the archives @ gerry.vanagon.com


The vanagon mailing list archives are copyright (c) 1994-2011, and may not be reproduced without the express written permission of the list administrators. Posting messages to this mailing list grants a license to the mailing list administrators to reproduce the message in a compilation, either printed or electronic. All compilations will be not-for-profit, with any excess proceeds going to the Vanagon mailing list.

Any profits from list compilations go exclusively towards the management and operation of the Vanagon mailing list and vanagon mailing list web site.