water flow ........ or lack of.

H

hindsight

Member
Hi. I have just discovered that I have got no water flowing from the inlet manifold "tower" on my series 1 V8.

I removed the hose that goes from the tower to the radiator and the outlet stub from the tower was totally blocked with what looked like years of "Bar Seal". I managed to remove this gunk with a 3mm drill and the outlet now seems clear, however when the hose is connected to this outlet I cannot blow or suck down it like I presume that I should be able to. With the engine running there is no water flow.

So my questions are.......

1. Should I be able to blow / suck down the hose or would the thermostat prevent this because it is shut ?

2. With the engine running should water flow from the tower from cold or does the water only flow when the thermostat is open?

3. Does the water flow from the tower to the rad or vise versa? ......... Not important, just curious.

4. Does it look like a inlet manifold off job to clear out the waterways ?

Thanks. Steve
 
The water flows from the tower to the rad, and it should do so all the time regardless of whether the stat is open or not. If you remove the end of the hose from the rad, and then blow through the hose towards the tower, then with the rad cap on you should get a spurt of water out of the open stub on the rad, if not you have a blockage somewhere. If you still have no flow then you will end up taking the manifold off and clearing it out through the core plug in the bottom.
 
Ok thanks. I thought that there should have been some flow.

The bloke that I recently bought the car off had been using it fairly regularly and I guess this would have been blocked for quite a while. Any idea what sort of damage would result in it being used like this ? Would the top end just get too hot ?

The only reason I ask is that I was hoping to use the car this weekend but don't want to do any damage. It wouldn't be any motorway journeys as it still has a vibration........see earlier thread......but I was looking forward to a weekend away doing 100 miles or so.

Just a thought.... there is a core plug in the very top of the tower, I don't suppose that it is just a simple case of removing this and having a "poke around" to clear out some gunk is it ??

Here's hoping Steve
 
hindsight said:
The bloke that I recently bought the car off had been using it fairly regularly and I guess this would have been blocked for quite a while. Any idea what sort of damage would result in it being used like this ? Would the top end just get too hot ?
Click to expand...

The normal symptom is overheating, followed by diagnosis of a failed head gasket. The latter is normally cured by cleaning out the pipe in the manifold.

hindsight said:
The only reason I ask is that I was hoping to use the car this weekend but don't want to do any damage. It wouldn't be any motorway journeys as it still has a vibration........see earlier thread......but I was looking forward to a weekend away doing 100 miles or so.
Click to expand...

Does it loose coolant? I'd want to know that before recommending anything. It may be that the hot running has been addressed by a lower temp thermostat, or removing it altogether, so now although it's running hotter than it should, it's not as hot as it would be with the correct stat.

hindsight said:
Just a thought.... there is a core plug in the very top of the tower, I don't suppose that it is just a simple case of removing this and having a "poke around" to clear out some gunk is it ??
Click to expand...

I don't think that the core plug on the top accesses the water jacket. If you search on here there are pics of someone who had your problem and posted a pictorial record of how to cure it.
 
It doesn't loose coolant but the temp does creep up when sitting in traffic. I put this down to an old looking rad that is presumably partially blocked. I haven't checked the thermostat to see what temp it is.

Think that manifold off will be my next step to avoid any damage.

Thanks Steve
 
hindsight said:
It doesn't loose coolant but the temp does creep up when sitting in traffic. I put this down to an old looking rad that is presumably partially blocked.
Click to expand...

The temp creeping up in traffic is normally an indication of the bleed pipe blocked. Ineffient rads will cause the same thing, but blocked rads tend to make it overheat at high speed as although there's a good flow of air through the rad then, the coolant can't get through the matrix quick enough to make use of the airflow, so the heat builds up. That said, having a good and efficient rad is a no-brainer regardless.
 
hindsight, as harveyp6 correctly mentions there is a small feed hole that allows coolant into the carby tower and this is what is most likely blocked.

see topic; viewtopic.php?f=5&t=9722&p=71730&hilit=carb+tower#p71730

and topic; viewtopic.php?f=5&t=14920&p=125082&hilit=carb+tower#p125082

I hadn't done it but you could remove the rear side core plug on the carby tower if you dont want to take off the inlet manifold and attempt to poke something down to unblock the small feed hole (the top core plug, once removed, has casting in the way which obstructs getting to the hole), if it is only soft crud but it can harden and may be better to get to it from the underside of the manifold as the hole is cast at an angle into the tower not straight up and down (if you get what I mean)

Regards,
Scott

EDIT; just adding photo showing angle of hole into tower




 
I would be thinking to get a bit of flexible wire in the hole and poking a bout a bit before tasking off the manifold.

Graeme
 
Hi guys.

Thanks for the advice. Ive not been around for a while and not had chance to reply.

Excellent photos......Thanks Scott.........Gives me a good idea of exactly where that darn hole is !!

I am planning to remove the manifold in the near future which means I will be able to give everything a good clean.

Steve
 
I just bought a second hand manifold when mine was blocked and swapped it on. It cost 10 quid or so from eBay, took a chance on it not being blocked and it wasn't.
 
cleared mine with a small jewellery screwdriver, hammered in and used a drill bit to bring the detritus out. Worked on mine....
 
Hi All. Just a quick question on this topic. A while ago I cleared the carb tower exit bleed pipe as described agressively with a hammer and small allen key. I do have a flow of coolant from this pipe when the engine is running. My question is this. When I take the carb tower hose off the rad and blow into it, (engine off & cold) I get a powerful jet of coolant from the pipe on the rad that this hose fits to. Does that mean that both the outlet pipe and inlet hole into the carb tower are both clear? I'm assuming so, but my carb tower still seems to get very hot. The engine also suffers from vapour lock in standing traffic/hot weather. Car doesn't ever overheat or lose coolant. I also have an MG header tank fitted, with a 0lb cap on the rad and the normal rad cap on the header tank. I have had an uprated rad core fitted, and completely flushed out the coolant system and used the patented 2 dishwasher cleaner trick too. I have also fitted a thermostatically controlled pacet fan and have done away with the fixed mechanical fan. Vapour lock is beginning to make me very nervous about driving in hot weather in case I get stuck in traffic, which is killing my enjoyment. I don't really want to go down the electric fuel pump route. I was thinking of fitting a heat shield to the fuel line into the fuel pump, and maybe another under the float chambers (HS6 carbs). I was also toying with the idea of wrapping the exhaust manifold with heat bandage.
 
V8P6B said:
My question is this. When I take the carb tower hose off the rad and blow into it, (engine off & cold) I get a powerful jet of coolant from the pipe on the rad that this hose fits to. Does that mean that both the outlet pipe and inlet hole into the carb tower are both clear?
Click to expand...

Yes.


V8P6B said:
my carb tower still seems to get very hot. The engine also suffers from vapour lock in standing traffic/hot weather. Car doesn't ever overheat or lose coolant. I also have an MG header tank fitted, with a 0lb cap on the rad and the normal rad cap on the header tank. I have had an uprated rad core fitted, and completely flushed out the coolant system and used the patented 2 dishwasher cleaner trick too. I have also fitted a thermostatically controlled pacet fan and have done away with the fixed mechanical fan. Vapour lock is beginning to make me very nervous about driving in hot weather in case I get stuck in traffic, which is killing my enjoyment. I don't really want to go down the electric fuel pump route. I was thinking of fitting a heat shield to the fuel line into the fuel pump, and maybe another under the float chambers (HS6 carbs).
Click to expand...

The only problem with an electric fan is that it's designed to cut in at a higher temp than a fixed fan should allow it to reach (because the fixed fan is running all the time), and when it does cut in it sucks all the heat from the rad and dumps it under the bonnet.......

Personally I'd rid myself of the HS6's in favour of HIF6's and see if that helps. If nothing else it should improve the economy.
 
Cheers Harvey. That makes sense. Anything I need to know about the HIF6 setup? What about marrying it up with the throttle linkage.?

I suppose I thought I was doing myself a favour with the electric fan. I figured that sat in traffic at tickover, the fixed mechanical fan was only spinning slowly, so not providing enough cooling when it was needed, whereas when you're travelling at speed, the fixed fan is spinning much faster at a time when there's loads of air flow through the rad anyway. That was my thinking behind it. I'm afraid I never thought about all the heat being dumped under the bonnet. It certainly does do that when the fan cuts in, you do get a blast of warm air coming from under the car. I did get vapour lock on hot days before I fitted it though. I'm wondering if a lower temperature thermostat might help a bit with the vapourlock situation. Its something I've struggled to cure. I've been through the whole cooling system, replaced all the hoses, flushed and backflushed the heater box and the engine, followed by the 2x dishwasher cleaner treatment, had the rad recored with a higher efficiency core, fitted an MGB header tank, with a 0lb cap on the rad, and moved the original cap to the header tank. It never overheats, and never loses a drop of coolant, and to be honest, on a hot day, the needle never goes above 1/2 way on the temp gauge, and vapourlock sometimes occurs even before the electric fan cuts in.

I think the next step may be to reroute the fuel lines from the reserve tap to the pump away from the exhaust manifold, or maybe at least fit a heat shield to it. I'm not really keen on fitting an electric fuel pump.
 
V8P6B said:
Anything I need to know about the HIF6 setup? What about marrying it up with the throttle linkage.?
Click to expand...


If you fit the carbs and manifold complete then it's a straight swap if you have the short kickdown cable.


V8P6B said:
I suppose I thought I was doing myself a favour with the electric fan. I figured that sat in traffic at tickover, the fixed mechanical fan was only spinning slowly, so not providing enough cooling when it was needed, whereas when you're travelling at speed, the fixed fan is spinning much faster at a time when there's loads of air flow through the rad anyway. That was my thinking behind it. I'm afraid I never thought about all the heat being dumped under the bonnet. It certainly does do that when the fan cuts in, you do get a blast of warm air coming from under the car. I did get vapour lock on hot days before I fitted it though.
Click to expand...

Electric fans are great, but in those circumstances they do dump a lot of very hot air straight on to the engine, a lot of which rises to where the carbs are. It will pull the temp down though. The problem with a manual fan is that once the temp rises it will struggle to reduce it, especially at idle.


V8P6B said:
I'm wondering if a lower temperature thermostat might help a bit with the vapourlock situation. Its something I've struggled to cure. I've been through the whole cooling system, replaced all the hoses, flushed and backflushed the heater box and the engine, followed by the 2x dishwasher cleaner treatment, had the rad recored with a higher efficiency core, fitted an MGB header tank, with a 0lb cap on the rad, and moved the original cap to the header tank. It never overheats, and never loses a drop of coolant, and to be honest, on a hot day, the needle never goes above 1/2 way on the temp gauge, and vapourlock sometimes occurs even before the electric fan cuts in.
Click to expand...

What stat are you running? If it's an 88, you could try an 82 (summer) stat. Another thing you could do is to replicate the problem in the garage, (or wherever) so you can see exactly what's going on. Sat on the side of the road isn't the ideal place to diagnose and fix it.

V8P6B said:
I think the next step may be to reroute the fuel lines from the reserve tap to the pump away from the exhaust manifold, or maybe at least fit a heat shield to it. I'm not really keen on fitting an electric fuel pump.
Click to expand...

You could try that, you could also fit an electric pump that you could just switch on as required to cure the problem at the point it happens, even if only in the short term to prove that really is the problem.
 
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