Mercedes-Benz Forum banner

1 - 5 of 5 Posts

·
Registered
1993 230 TE.1999 om 606 td. and 722.6 3.2L,clk w208 1987 Kit car with 260e running gear.
Joined
·
733 Posts
Discussion Starter #1
Hi all,
Thanks for the replies earlier this year regarding the replacement of my 2.3 petrol engine with a 2.5 diesel 5 cyl non turbo.
Transplant is finally done and as predicted will win no speed/performance prizes but I am delighted with it and the old bus will hopefully go for years as only 110k miles on the engine currently.
Great to have no electronics other than the glow plugs relay because I had nothing but grief with my c220cdi estate (wagon;)). 2003 model and sold it recently for pennies as it wouldnt go higher than second gear.
Sorry to ramble on, my current issue is with the heater in the 230 (250d)TE.
Even before I changed the engine I noticed the heater wasnt great and particularly cooler on the driver side (uk).
I ve been through many threads on the subject and note the differences in models with duo and mono valves etc.
That aside, they all have a heater matrix and I wonder if anybody has had issues with them losing efficiency to the point where they just dont seem to work, I suspect internal sludge/crud.
There is 125k miles on the car and so far I have bypassed the duo valve with a ' y' piece, reverse flushed the matrix, stripped the control panel and operated the control wires and flaps by hand, removed and bypassed the pump and the result is always the same.....2 minuites heat then cold whether on screen or cabin.
1992 230TE UK spec and no a/c.

Help:surrender:

Boyd
 

·
Registered
Mercedes 300 TE 24v SportLine -91 W124
Joined
·
158 Posts
As from I understand You have dual temp regulation, right!?
Anyway, You may have the same problem I had before.
I could never get a good temp. Warm in the beginning and suddenly rather cold.
The only way to get it warm was to set it on max.

The fault I had was in the thermo dial. Probably because the car had been not used for 3 years and the vari. resistors had corroded.
I changed the whole unit in the console and all was good.
 

·
Registered
1993 230 TE.1999 om 606 td. and 722.6 3.2L,clk w208 1987 Kit car with 260e running gear.
Joined
·
733 Posts
Discussion Starter #3
Thanks JY

Problem is that my understanding is that the dials operate the duo valve, via the control box. I have the duo valve removed and bypassed :confused:.

The fresh air in/ recirculating is done with a cable from the fan speed switch and the higher the setting the more fresh air it allows in.

While I had the control dials stripped I operated the cable by hand and found it to be in order:confused::confused::confused:.

Boyd:crybaby2:
 

·
Registered
Mercedes 300 TE 24v SportLine -91 W124
Joined
·
158 Posts
Thanks JY

Problem is that my understanding is that the dials operate the duo valve, via the control box. I have the duo valve removed and bypassed :confused:.

The fresh air in/ recirculating is done with a cable from the fan speed switch and the higher the setting the more fresh air it allows in.

While I had the control dials stripped I operated the cable by hand and found it to be in order:confused::confused::confused:.

Boyd:crybaby2:
Yes the dials operate the duo valve but also turns on/off the heater pump.
If You bypass that pump You will not get sufficient water flow to the cabin.
But as You have bypassed the valves You SHOULD get the same temp on both sides of the cabin.
If not You probably have crud and dirt covering the heater matrix.
That would be my guess.

Maybe there is a chance of reversing the cables to the intake fan and suck out some dirt.
Otherwise You will be in dire need of a big disassemble.:eek:
 

·
Registered
1993 230 TE.1999 om 606 td. and 722.6 3.2L,clk w208 1987 Kit car with 260e running gear.
Joined
·
733 Posts
Discussion Starter #5
Fixed it:thumbsup::D.
Decided it could only be an internal crud blockage and set about fixing it.
I disconnected the return at the engine block and the flow at the battery (UK).
Hosed it through with alternate hot and cold water and from both sides.
Clamped the returns to the duo valves one at a time to prioritize the individual heater elements.
Then linked the flow and return with plastic plumbing pipe including a tee piece for a small plastic tank/filler at higher level , almost like a small heating system.
Put in soome Holts Radflush and boiling water and ran the pump with ignition on for half an hour.
Now it all works great:).
I reckon PO has tried to fix the faulty radiator with Radseal and it has congealed in the heaters. I didnt help either with 3 egg whites:eek:.

Boyd:)
 
1 - 5 of 5 Posts
Top