I have just completed my windscreen repairs and got the screen back in. Only the rear to do!

I have a few heater issues. Firstly even when the fan is on the second setting there is little output, particularly up to the screen. Also when the heater is on hot what little air there is, is not very warm even when the engine is hot. Any ideas? A further complication is that it has an LPG conversion and the cooling system has been modified to heat this also.

As I have the dash out at the moment due to the windscreen repairs I want to sort this now, not later

Secondly, do 130 Coupe bumpers fit the saloon?

Hi saloon and coupes have differant bumpers!

I know they are different, but do coupe bumpers fit a saloon? I have seen a photo of a coupe with a saloon front bumper and it appeared to fit.

As much as I have always admired the look of both the 130 Coupe and saloon, I haven't a clue about how to fix them.

However, if this was a modern car we were talking about, I would check both the heater/blower switch and resistor/blower motor. Also, is it possible there are any air locks in the coolant system?

Thanks for the ideas John. I'm thinking it could be to do with the LPG conversion. I might try the cooling system as it would have been when it left the factory and see if this makes a difference.

With regards to the blower motor side of things the fan runs at two speeds, but not much air seems to appear. I think I might have the heater box out and have a look.

Hello Dave,

It is some years since I overhauled my Coupe heating, so this is from memory.
Firstly try to avoid removing the heater matrix if possible - especially if your car has air-conditioning. It is a nightmare to get everything back together without damaging the matrix or the a/c intercooler (or whatever it is called) that sits above or below the heater matrix. (I can't remember)

Check that there is hot water going into and coming out of the matrix - the hoses are easy to locate passing through the bulkhead.

Check the hot/cold valve operated by one of the cables is working - mine was seized.

Next try to release any air that may be in the matrix by loosening the exit pipe.

If hot water still does not flow you will need the matrix repaired. This is unlikely I think - mine was returned by the repairer because there was nothing wrong with it. (I had sent it anyway with the main radiator for reconditioning)

If you now have hot water in and out, but little or no heat, the vent flap may be jammed shut. Check that the cables are actually opening and closing the flap. The car relys on a ram effect for best result of the heater, with the blower as back-up when stationary or slow-moving.

From memory again, I think there are 4 speeds for the blower motor, but 1 and 2 were not much use! And I think there is a strange roller type of 'switch' to direct hot air to the windscreen, so make sure this is operating.

I am sure none of this is 'by the book', but hope it helps?

regards Richard (and no thanks, I don't fancy doing it for you!)

Thanks for the ideas.

Firstly no air con so that will make things easier.

Secondly I only appear to have two positions for the blower switch (three if you count off!) My car is a 1972 model, perhaps the later coupes had a different set up? If so I may upgrade. The dash is already out so now is the time to do it!

With regards to water flow, I have tested the valve and know this works fine, when open the water flows, when shut it does not. I also knows water flows through the heater matrix. When the engine is warm the radiator and radiator hoses get hot but the heater pipes do not get very warm at all. As I said my car has had an LPG conversion which includes some modifications to heat it. This involves the water flowing through the heater then down a long pipe, through the LPG and then back to the engine via another long pipe! I have checked all these and they are not blocked, however they do not get very warm. My thoughts at the moment are that due to the much longer lengths of these pipes than standard the water pump is not able to circulate the coolant round these and it is therfore just sitting in the pipes if infact the pipes are full at all. The Mercedes I have has an inline electric pump near the heater to pump the water through it, I was considering using a spare one of these to see if it helps. Alternatively I could disconnect the water pipes for the LPG and return the setup to standard to see if this improves things.

Just a thought - can you clamp the LPG derived hoses so that water cannot flow at all through that system, and then see if the heater pipes becomae warm by bleeding the heater system as above?

The LPG is completely alien to me, but it does sound as if you do have an air block in the heater circuit, or a blockage in the matrix.

Before dismantling, do try and get hot water to run through the matrix.

I think the non-a/c had different heater controls?

Good luck

regards Richard

The coolant needs to flow through the heater and then back into the engine. If I clamp a pipe it would not be able to flow back to be reheated. I can either put the pipes back as they originally were or add the pump into the system. I think I will try it as it was in the factory to verify the LPG modification is infact the problem. I will let you know how I get on.

Hi dave,my 130 didnt have a overheating problem but a bit hotter than it should,i found the metal pipes and the water intakes to the carb had blocked up,cleaned and replaced ,then usual new stat flush etc ,fine now,dont think this will cause a major overheating problem but if your going through your cars cooling system may be worth a look

Mine were not too clever either, but I took care of this when I rebuilt the carburettor. I also flushed the cooling system out with a two part flushing system and then refilled it with new antifreeze mixture.