Back for help coolant problem

[Bryce]

Hello again!

With the help of this group I recently got the fuel pump refurbed and replaced glow plugs and timing belt

I seem to have jumped from one issue to another recently. Ive not long took it for a very short test drive (less than a mile) when I started hearing noises from engine that I didnt like the sound of, I thought it may have been the sound of a misfire as one of the injector pipes was leaking.

When I pulled onto drive the engine was really hot and a couple of times had started revving itself without pressing the accelerator so left to sit overnight. Started it again this morning and again seemed to get hot very quick while idle.

Checked coolant hoses and only the ones nearest the engine were hot I also noticed bubbles in the coolant tank when pressing the accelerator which from what I've read is definitely not good news.

I'm guessing the first thing to try is to rule out any air locks but I'm reluctant to have the engine running for any length of time in case I cook it.

There is pressure in the coolant system after turning the engine off and in the short time I had it running the radiator was still cold as was the pipe leading to it in the engine bay. The dalek cap is new as are both coolant tanks and there are no viable leaks.

Whats the best way to try and diagnose the problem? Surely I can't of cooked the head gasket by driving less than a mile and not getting out of third gear?

Any help is much appreciated

[Stesaw]

Check to see if the rad is getting hot. If not bleed the system from the rad, make sure your heaters are on as well when doing this.

I guess firstly you could check your thermostat is opening. Take it out and put it in some boiling water if it opens then all good, if not order a new one.

[RogerT]

Revving itself? How’s the oil level? Had this with a Td5 Disco that started filling the sump with diesel, but that was a very different engine design. Not a good sign though I’ll wager.

[Bryce]

Yeh it was sitting at idle while I tried to nip up the leaking injector pipe and it just revved as if someone had put their foot on the peddle. I ran round the front it and seemed to settle itself before doing it again e few mins later.

I googled it and managed to scare myself with stories of runaway engines ha.

The thing is all the work I've done hasnt touched the coolant system and it ran fine before. Will see if I can try and bleed it today but I'm just worried about it overheating

[Bryce]

Sorry the oil level seems fine between the two dots on dip stick

[Bryce]

OK so just started it and let it sit idle for about 10 mins. When I loosened bleed screw on radiator I straight away got coolant coming out. Checked dalek cap and for any blockages to expansion tank.

After 10 mins it looked like this with radiator still being cold(not sure if I gave it enough time).



After about 5 mins I would get a short pitch drop in the engine noise and would throw out some black smoke with a bit of a knocking noise then return to normal.

Anyone have any ideas or know anyone in the North East I can bribe to come have look?

[RogerT]

You might have more than one thing going on, the revving and the coolant, at least.

Regarding coolant, does your heater get hot? There’s no thermostat in the way and it would tell you the water pump is doing some work at least.

Have you checked the thermostat as Stesaw suggested?

How old is your radiator? Might it be full of crud? The diagram you posted suggests there is no flow to the radiator and they do get full of crud with age. Flushing might help, but if it’s ancient you might be better off replacing.

Sorry I can’t help with North East, but the sad truth is these vans require deep pockets or gritting your teeth and doing it yourself. Most of us have been there. I realised o couldn’t afford to get the van maintained after a month of ownership, having never spannered on a vehicle before. Steep learning curve, but the forum has been invaluable.

[Bryce]

Thanks for the help. Not sure on radiator age but is not the original as has different hex bleed screw than any I've seen in manuals. The thermostat I will test this weekend.

With the cap off coolant tank the level rises and falls with acceleration so I can assume the water pump is doing its job I think

The problem is I'm in a bit of a catch 22. I can't rev the engine to get the coolant going and temp up as it has quite a bad knock starting at higher rpm and I don't want to get the engine too hot before I know the coolant is actually circulating!

The temp gauge on dash works but when it's at a quarter way up the engine seems pretty hot

To add to this my heater doesn't work so although I have it set to high I assume it would need the van moving to push the hot air.

The rev drop Ive diagnosed as air in the fuel line and seem to have fixed

Will try and post a video later of the sound of the knock.

Think my only option is to start again with checking all the timings. Be my third rocker cover gasket purchase in 2 months!

Sorry for the long post but I'm a bit stuck, I just don't want to cause some catastrophic damage. On the bright side I've learnt a hell of a lot from you guys but I would give a lot for a obd port on these things

[Stesaw]

If you're getting a knocking at high revs there might already be damage to the engine. I'm not clued up on diesels but knocking is never a good indicator.

[Bryce]

Yeh everything I have read seems to say its not going to be good but would be nice to find out what it is that's knocking,

runs lovely in fact better than anytime since I've had it untill you hit a certain rev range and the knocking starts then dies away when back down with the revs.

Will get the cover off and re check all the timings. Although triple checked and turned it over by hand a lot before I turned the key (after changing belt and fuel pump)

Guess the knocking is more important than the coolant problem so will get at that one first

[RogerT]

Guess the knocking is more important than the coolant problem so will get at that one first

I’d agree with you there. Fraid I can’t help with the knocking, beyond my expertise.

[Timburrows]

Re the knocking,have you checked the valve clearance,as the engine warms up the clearance reduces,as for getting hot? The gauge should sit around the middle,normally the rad fan will come on at about three quarters,the heater will be putting out hot air after a mile or so if all is correct,the red light will flash when overheating is occurring,this is taken from the header tank with the blue cap on,if the head gasket is leaking it will also flash as the combustion gas is hotter than the water so temp gauge will read normal but the light will be flashing,the light will also flash if the water leaves is low,the knocking may be due to the timing being set incorrectly

[Bryce]

I paid a garage to set the clearance a few months ago (wish I'd just bought the tool now)

The knocking or clacking I made a new thread about as it seems the most important I've took a video to show the sound

https://youtu.be/9WGnVZjtJsk

Before all the work the temp needle didn't work until I replaced it with a cheaper one from bw as they were out of stock of the better one. It always sat just to right of the led on dash. I'm not sure if I'm just panicking about overheating the engine and can't give a good run due to the noise.

I'm getting a injector looked at tomorow and have a new reusable rocker gasket on the way so I can check the cam follower suggested in the other thread. Next time I get it working I'm just going to leave my spanners in the garage!