Coolant hose on its way out?

[mikeonb4c]

Apologies for asking this Mr Halibut but I don''t want to re-read the whole thread:

* Has a new radiator beend fitted? If not, then I imagine a new one could help things.

* Can you be sure the radiator fans are coming on when engine temp sensor is asking for max cooling effort. I found it easy to supply a direct live feed to my scavenger fan and fit an over-ride switch. If you could find a way to temporarily force the radiator fans (scavenger fan is not really important for rapid coolant cooling) to run all the time while you carried out the same tests as before, it would be interesting to see the result. If it seems to do the trick, then you have a possible solution. You can:

1) Find out if the temp sensing switching circuit for the rad fans etc. is misperforming, then fix it and see if things improve.

and/or

2) Fit a manual switching feed/switch to the rad fans so you can switch them on when you need to. You really want a proportional temp gauge readout so you can see when temp is starting to rise. Fitting a Mason Alarm would make your gauge much more useful in tthis respect. And here it gets interesting. Because since the Mason has a user adjustable temp. trigger point that set off an alarm, there is no reason why that circuit should not be tapped into in order to switch on rad fans using your new wiring supply. And by adjusting the Mason knob thing you can effectively switch rad fans on and off at will.

Now there's some stuff to think about over a cold beer or six

[Mr Halibut]

I have:
Replaced the 4 main hoses
Thermostat
Antifreeze
Fitted low coolant alarm

When I emptied the system the coolant came out clean. The previous stuff had been in there 6 months from when I bought it. I flushed the system out especially the rad and it all seemed good and clean.
The radiator fan does come on, I checked during the bleed after it was up to temp. I could try and rig something up to check if they are still running during the hill climb just to see if there's something funny going on.
The scavenger fan is a good question, I have never ever seen this fan running although I thought it was more to do with idling on a hot day to circulate air whereas hooning up a hill at 70 would provide air circulating from up under the car. I checked the main fuse and that seems ok. I'll do a search for where the sensor is located and see if i can trick it into coming on just to test it.

I thought about buying a Mason alarm, do you think I can get a discount having the same surname? Perhaps a distant relative?

It is a pity I don't have results from before the change although I have been up some fairly steep hills with a bongo full of stuff and a caravan on tow maintaining 50mph without the gauge ever budging before (there goes ever selling my bongo on to a member who reads this ).

[mikeonb4c]

Don't worry (much about the scavenger fan - you are right in what yo usay, and it's not going to be a cause or a cure).

I can't help but wonder but a new radiator might do to improve things. Someone on here did talk about how to do a crude flow test on the radiator. But replacement costs £100+

I think you'd be very wise to fit a Mason alarm, given you plan to work the engine hard (which it should be quite capable of allowing you to do by the way). Only £27. Mind you I belive he's suspended selling them while he modifies the design. The TM2 engine block temp sensor would be a more expensive alternative but I'd prefer the Mason here as it is measuring the coolant temp direct, plus the designer posts on here and could advise on using it to trigger a rad. fan switch.

If it were me, then just out of curiosity I would try rigging up a temporary over-ride circuit to the rad. fans just to see what beneficial effect it might have. The way the temp creeps up does suggest that some combination of ineffective water cooling and ineffective water flow might be to blame (can the water pump lose efficiency while still appearing to work from the outside, for example).

I assume there are no symptoms of exhaust gases blowing past head gasket and into coolant?

Sorry if this is going over old ground. It's hard to type a post and see all the previous posts at the same time.

Maybe other more expert members will chip in with thoughts

PS - don't waste any more money refilling with antifreeze mix until testing complete. A short period on pure water shouldn't do any harm. I wonder if it is even possible to save the 50/50 mix in a clean container for re-use when testing finished. Can't think why not!

[Mr Halibut]

I will definitely be draining the antifreeze and re using it if I need to drain it.

I might get a few of those temperature guages if they are cheap, one on the auto box too.

I haven't noticed any exhaust gases in the coolant. I also check for white smoke at start up and for water in oil, oil in water but so far nothing. I am in fear of blowing the head it if I haven't already.

I had the old girl running for a long time and the bottom pipe was very hot. I am going to try one more bleed tomorrow and see if I can extract any more air.

[Mr Halibut]

Nope, no good. I spent an hour bleeding the system and it was red hot. I got a flow of little bubbles coming out every time i raised the level of coolant in the pan which is what i got last time and then they seemed to stop after about 40 minutes, I kept going for another 10 minutes and they seemed to stop but I am pretty sure this is what happened last time...

Looks like I am going to have to drain the system again and try to find out what's going on.

[Mr Halibut]

Some pics of me doing the bleed. I also took some footage but you'll need quicktime to play them.







http://www.surferus.pwp.blueyonder.co.u ... V00252.3GP

http://www.surferus.pwp.blueyonder.co.u ... V00255.3GP

[lizard]

Just a few thoughts


Dont really know, but with a mason alarm fitted driving around at any speed on the flat all is well, gauge is at 12:30 1:00. Caining it up hill the gauge moves over 2:00 2:30. This is a bit worrying. I ease off and slow down on nasty hills. Not sure if anything is wrong or not. Driving normally all is Ok. I have never heard any of the fans come on. The rad fans work with the air con on.

[Mr Halibut]

Right.. Spent a lovely day draining the system and removing the thermostat. We tested the new stat against the old stat in a pan of water and the new stat opened faster then the old one and opened about the same amount so there's nowt wront with the stat.

We put it all back together (with the new stat) and bled the system again using the same method as before and took her for a moderate spin 40-60 mph for 10 miles with no problem. I might try a cold bleed in the morning

We had the car running idle and at 2500rpm for about 1hr 30mins and during that time the bottom pipe nearest the thermostat was very hot but the bottom hose that comes straight from the rad seems to be impossible to push above 'warm' without driving it. The rad fans didn't come on until after the drive either.
The top of the rad gets hot but lower down there's it becomes cold.

This leads me to believe that:
a) We are numpties and can't bleed it.
b) Using mIke's theory the flushing and refilling of the system (I put radflush in it before i drained it and let it run for 10 mins) has distrurbed something and blocked the rad enough to lower its efficiency. I did notice after looking at the old thermostat after it had dried off that it has a lovely layer of limescale on it meaning its had some good olf fashioned tap water in it at some point.

To rule out 'a' I will try and get a professional to bleed it and then see what happens. If this doesn't help i guess i'll have to invest in a new rad.

[lizard]

Sorry I digress.

In the third pic, What's the flangy bit, (sorry about the technical description) above the hose. Mine has oil seeping out around this. Is this a problem

[missfixit70]

Sorry I digress.

In the third pic, What's the flangy bit, (sorry about the technical description) above the hose. Mine has oil seeping out around this. Is this a problem

Air intake manfold, most of them leak a bit ,especially if the egr is still in use, nowt to worry about as long as you haven't overfilled the engine with oil & the turbo is pulling it up through.

[lizard]

Sorry I digress.

In the third pic, What's the flangy bit, (sorry about the technical description) above the hose. Mine has oil seeping out around this. Is this a problem

Air intake manfold, most of them leak a bit ,especially if the egr is still in use, nowt to worry about as long as you haven't overfilled the engine with oil & the turbo is pulling it up through.

Thanks for the advice and help. I had better check.

[Mr Halibut]

Tonight i decided to have another play with my Bongo and something odd happened. Or it may be normal, I am unsure.

I filled my trusty coolant jug half way with antifreeze and plopped the bleed pipe in, plug out (engine not running and cool). I dropped the measuring jug (with bleed pipe in) way down below the level of the expansion tank and i could hear a strange honking noise (like a canadian wild goose) coming from the expansion tank and the measuring jug was filling up. The expansion tank lid was on but the level was dropping and the jug was filling up. If I held the jug up above the tank it filled back but very slowly and nowhere near as much as I got out.

I was under the impression that the expansion cap created a complete seal and the only thing that could change that was excess pressure through the overflow pipe. Stranger still is if I drive it and leave it until cold you still get a slight pshht noise when you take the top off as if pressure is being stored in the tank.

Is this normal? honk honk?

[Mr Halibut]

After a few searches it seems it can allow air in but not out... I think I need to stop sniffing boiling antifreeze.