The good old Eberspacers again...

wshawn · Post by **wshawn** » Wed Dec 03, 2008 10:20 am

Now it is very cold again here I thought I'd try the Eberspacer to thaw out the car.

It kind of half heartedly fired up and got warm but then would not fire up again.

It seems to only like running when the air temp is freezing and the car is cold. As soon as either get slightly warmer it decides it has had enough and blows one of the safety fuses.

I'm assuming then that there must be a temperature sensor that is faulty, if this is the case is there a work around that is safe or do I need to try the near impossible task of sourcing a replacement sensor.

Once the car is moving along I get plenty of heat from the Type 2 heat exchangers, it is just the amount of time and distance covered with ice keep on forming on the screen which is the problem.

Wally · Post by **Wally** » Wed Dec 03, 2008 12:46 pm

Maybe its just a matter of cleaning the electrics properly?
Because its old, doesn't alwys mean its broken

SiQDiZ · Post by **SiQDiZ** » Wed Dec 03, 2008 1:12 pm

You can find schematics on the internet how to troubleshout the electronics. Google and thou shalt findeth

Also check the fuel line for clogs.

412s2 · Post by **412s2** » Wed Dec 03, 2008 1:23 pm

I agree with Walter, mine usually fires up after cleaning the spark plug and other electrics. I find if you use the Eberspächer often, it tends to keep working, it's only when it's been sleeping for a while that it's a little reluctant to wake up!!

wshawn · Post by **wshawn** » Wed Dec 03, 2008 1:30 pm

It was a tad smokey yesterday when it awoke from its hibernation, shall try and check all the connections and pipes at the weekend as I need it to get to work every day now that I have rejoined the working masses

wshawn · Post by **wshawn** » Thu Dec 18, 2008 10:03 am

Have found a small hole in the Eber exhaust that needs fixing and other than that it seems to work well so long as I don't crank up the heat too high.

raygreenwood · Post by **raygreenwood** » Thu Dec 18, 2008 2:20 pm

What happens when you crank the heat up too high? Ray

wshawn · Post by **wshawn** » Fri Dec 19, 2008 6:38 am

It blows one of the safety fuses.

I think it might be an overheat cut out thingy. I need to fix the holey exhaust and make sure the pipes that blow the air through the unit are all tightly fitting without holes.

raygreenwood · Post by **raygreenwood** » Fri Dec 19, 2008 6:46 am

That would be the 25-30 amp fuse (if memory serves)...in the black inline fuse holder near the main relays.....with the olive green wire going to it?

If so that is the high limit/over temperature switch located under the rubber plug in the top of the chamber.

This generally means that you are pumping too much fuel...or too little air.
When the unit is cool, you need to have a graduated container ready. Unplug the fuel line that goes between heater and pump...at the pump. Have someone turn on the pump and measure how many mililiters of fuel flow into the graduated tube in 30 seconds and then one minute.

I would have to check my books....but its something like 5-10 mlliliters per minute. It is adjustable at the output nipple of the pump. Ray

MGVWfan · Post by **MGVWfan** » Mon Feb 23, 2009 4:24 pm

Hot air flow from the blower in the engine compartment could also be too low. If it works OK while the engine is revved up, but pops the fuel pump 8A fuse when at idle, that might be it. Go over the ductwork and exhaust heat exchanger tin for leaks, and check the blower motor for good airflow.

herr_sparky · Post by **herr_sparky** » Sat Feb 28, 2009 12:34 pm

wally, can you describe what needs to be done to use T2 heat exchangers on a 412? i removed my eberspacer a long time ago and run ducting straight to the fresh air tunnels with a toggle switch for the booster fan. would the T2 heat exchangers provide better heat?

wshawn · Post by **wshawn** » Sun Mar 01, 2009 2:24 am

Type 2 heat exchangers are proper heat exchangers with fins on the exhaust pipe section that runs through the outer casing of the unit. The Type 4 ones are more of a plain pipe without the fins, hence less surface area and less heat.

Firstly you need to check the shape of the exhaust manifold to make sure you get the correct Type 2 heat exchanger. You might need to do a bit of reshaping to the left hand side outer case to make it fit around the oil filter. Other than that they bolt right up. The holes that connect to the blower pipes might need some attention as well as they are different shapes.

All the small mods are worth it as they do provide more heat and I'm not alone in that thought as I got the idea from another member in our local club who has done the same.

wildthings · Post by **wildthings** » Sun Mar 01, 2009 8:17 am

When I get my 411 back on the road again it will have T2 heat exchangers in it. I am figuring that I will not need to run the gas heater except to get a quick warm up. In the long run I was thinking of maybe eliminating the gas altogether and added these little inline booster fans.

http://mechotronix.com/blidge-blower.htm

Or at least something similar, maybe some form of centrifugal fan that will be quite while really moving the air. From experience with a bus, if you can double the air flow your will get a major increase in not only volume but temperature at the defrosters as well. Adding a booster fan to a bus bumps the temperature to the front by 30°F or so, very noticeable.

Don't know how you would do just adding booster fans with the stock T4 heat exchangers. It might actually do pretty well.

There is a new set of T4 heat exchangers on eBay right now. I would not think that the guy will get any bidders with his overly high starting price though, would rather spring for a set of Dansk bus exchangers myself if I am going to pay that kind of money.

herr_sparky · Post by **herr_sparky** » Sun Mar 01, 2009 8:54 am

yep...$300 starting bid

its too bad theyre so hard to find, i'd really like to try this out...

about the booster fan: the stock fan is actually quite good at moving air up to the cabin, and it stays pretty warm once it isnt circulating through a cold metal chamber (non-functioning eberspacer). by giving it a direct power source and installing a toggle switch you can force it to run whenever you want, and since its in the engine compartment you can barely hear it. this setup works pretty well for me, but it never gets really cold here, either.

wildthings · Post by **wildthings** » Sun Mar 01, 2009 1:46 pm

The difference between using the stock fan in the engine compartment and an inline fan is potentially huge. The stock fan can contribute volume only when its pressure output meets or exceeds the pressure output of the engine cooling fan. An inline fan boosts the pressure and therefore the flow of air under all conditions.

The increased volume you get when running a booster fan, means a smaller percentage of heat is lost on the way forward increasing the air temperature at the outlets.