I have a 2005 CRD with a very small leak from the viscous heater. I have had the viscous heater relay pulled for about two years. Where I live, it never freezes, so I do not need it to heat the motor or cabin. It uses a quart of HOAT every two to three weeks.

A new viscous heater is cost prohibitive and I never use it. Can I bypass it by directly connecting the input heater hose of the viscous heater to the output heater hose? Has any one ever tried this? Is there another alternative?

Thanks, uham

Can you post pictures so we can see where it is leaking?

DOC

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2005 KJ CRD Ltd Detroit TrueTrac Bilsteins G2 GDE "HOT" ECU GDE TCM "Tow Tune" "euro" TC SEGR Weeks Elbow New HG at 130K ARPs Clean CAT aFe Filter Magnaflow Exhaust EHM Cumminos In-Tank Lift Pump Hayden Fan Clutch Nylon Fan VH Enabled with GDE lower shutoff point Recalibrated Temp Gauge Tekonsha Prodigy Sears P-1 ZDDP

I've not heard of anyone doing this although a number of us are running with the viscous relay pulled so the clutch never engages and at least one member a while back (viewtopic.php?f=5&t=60567) was running with no clutch all apparently with no problem. As I recall the guts of the viscous consist of a) the bearing, b) the electric powered clutch which is engaged/disengaged by a signal from the ECU (I know the GDE tune changes the coolant temp trigger points) based on coolant temp, c) some sort of friction discs inside in like a silicone fluid that rub together to create heat, d) coolant passage(s) to pickup the heat and send it on to the heater core.

With the relay pulled so the clutch never engages, assuming it's not locked up like in the post, the friction plates don't "do" anything and water just passes thru the housing to no purpose. On that basis I see no downside to simply pulling the viscous heater hoses and routing the flow from the tstat straight to the heater core.

Like Doc I am curious about the leak. A quart of coolant lost every 2-3 weeks is a heck of a leak unless you do a lot of driving so I wonder if you have other leak points.

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Sold to LOST member my 05 Ltd, GDE Stg II turbo + TCM tune, SunCoast TC w. Transgo kit, Steiger window regulators, Samcos, Fumoto valve, 2nd gen filter head with Lub. Spec. bleeder, Hayden clutch & 11 blade fan, inverted spare, P-1 battery, BF Goodrich Long Trail TAs, Etecno1 glow plugs, timing belt at 50K miles/8 yrs

I would like to supply photos of this problem but I can not get a camera where the leak is occurring so I will do my best to describe the leak.

The top of the viscous heater looks completely normal with no moisture or discoloration from moisture. The input and output heater hoses are in good condition and do not appear to be leaking. The leak is on the bottom of the viscous heater where coolant droplets are forming. They appear near a round seal [freeze plug?] on the bottom of the unit however I would not count out a leak from the bearing on the pulley clutch assembly. I just can not see it clearly enough.

I wonder if the long term affect of removing the viscous heater relay is somehow related to this?

I have now bypassed the viscous heater by splicing the input to the output hoses. I hope this solves my problem until I get home. I am currently traveling and should be home in a few weeks.

I am also concerned that there may be multiple leaks but I will know more after a few days on the bypass.

When I get home I will remove the viscous heater and examine it to determine the fault.

Thanks, uham

I see no harm in bypassing the heater. I like the idea of having it for cold weather personally. Quicker warm up times which is better for the engine. Diesels are naturally slow to warm up due to their efficiency. Keep us posted. I, too, am curious as to where the leak is coming from. It is the first one I have heard of that has leaked. I am wondering if there is a company out there that rebuilds them. IIRC it is a Japanese built heater. The company escapes me at the moment. It is pretty simple to remove it. It is a fairly small and light weight unit.

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Mike Rausch
Bear, Delaware
2006 Liberty Sport CRD 253K

You should be able to snag one used from a member here. Search the forums and I'm sure you'll find stories of totaled vehicles, e.g. flood damaged, fire, accident, etc...etc...

Update, 2 months later:
Well I bypassed the viscus heater but still had the problem.
When looking up from the bottom of the jeep the leak looks like it was coming from the viscus heater but it was coming from the water pump.

Replacing the water pump is a big job on the CRD so I had to wait to get some place where I could work on it.
I towed the Jeep behind my motorhome and 1,200 miles later I was home.

Since my CRD had 96,000 miles on it, it was also time to change the timing belt.

Timing Belt Information:
I ordered the parts from idparts online and they arrived very fast.

TOOLS: I did not have any special tools to do the timing belt and water pump replacement so I had to build some:

1) To get the fan blade off, I had to extend my large adjustable wrench.
I used a 30" piece of 1" emt conduit and wacked one end of it with a dead blow hammer.
This created an oval shape on the end that would go over my large adjustable wrench.
This gave me the leverage I needed to brake the fan nut free.
Also, I used an alan wrench in the hole on the bottom of the pulley to lock it in place while removing the fan nut.

2) To lock the cam shafts in place, I ground down 2 bolts as specified by the beesvillebeefarm online procedure.
They were not difficult to make using a bench grinder and ruler. They worked well.

3) In order to torque the cam sprockets, I had to build a tool that I could leverage against while removing and replacing the cam sprocket bolts.
I used 2 24" pieces of 1/2" emt conduit and joined them at one end with a 1/4" bolt to make a "V".
At the other ends I drilled 1/4" holes and installed 1 3/4" bolts, locking them it place using 2 nuts.
This was a crude copy of the tool used in the beesvillebeefarm online procedure but it worked well.
If I had it to do over again I would use 3/4" emt conduit and larger bolts.

4) Next I needed a tool to tension the timing belt. This was a puzzler.
The holes in the tensioner are very small and using small bolts/screws would not be strong enough.
What I came up with is using a piece of 6" x 1" x 1/8" aluminum stock and drilled two small holes at one end the same distance apart
as the holes in the tensioner.
I inserted the short end of a small alan wrench in each hole.
I held the alan wrenches in place with my fingers and aligned them into the timing belt tensioner pulley.
I was able to hold the correct tension while I torqued down the timing belt tensioner pulley bolt.

Observations:
A) Loose timing belt: After 96,000 miles on my 2005 CRD the timing belt tensonier was almost all the way out.
It may be necessary to change the timing belt based on 100,000 miles or 7 years, whichever comes first.
Eight years may be too long.

B) Water pump pulley wobble: The water pump pulley could be wobbled with hand pressure.
I wonder how many more miles I had before a catastrophic timing belt failure?

C) Run motor then recheck tension: After installing the timing belt, prior to putting every thing back together,
I found that running the motor a few seconds caused the timing belt tension to change and had to be re-tensioned.
I would recommend doing this. It does not take that much extra time.

D) CRD idled smoother: I purchased my CRD with 73,000 miles on it and it always idled a little rough.
I thought it was normal or maybe one of the injectors was fouled.
I used injector cleaner on a regular basis and this improved it slightly.
After the timing belt change, my idle is very smooth and there is no hesitation when accelerating.
I do not understand how changing the timing belt could improve idle and hesitation, but it did.

E) The water pump from idparts online fit into the existing water pump housing. This simplified the water pump replacement significantly.

I have put about 1,000 miles on it since the timing belt change and everything runs well and no more coolant leaks.
If you would like photos of the tools please let me know and I will add them here.