Am I being stupid or am I missing something?

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2rovers
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Am I being stupid or am I missing something?

#1 Post by 2rovers » Tue Feb 21, 2012 5:49 pm

Hey folks, I replaced the girlfriends 416 head last year around April / May.( rephrase that, engine head not gf's head!!)
All has been fine and well, she's ran absolutely great, and after many a thrash around she still worked fine, up until about 4 weeks ago!
We had a couple of nasty frosts here, and having forgot to put anti freeze in, I didn't use her much.
Now, I've replace all the fluids etc etc and she worked great again, no overheating , no problems , zip all wrong.
After doing the school runs over the last week I've noticed that she seems to be boiling up , the water that is, the engine runs sweet as a nut, no mayo indicating hgf, now after a ball ache in emptying the system again, and refilling , and another blast up the road she's getting hot again. What's actually happening is that the water in the reservoir starts to get to the top blowing water out, eventually the fan kicks in and the water returns back to normal level.
Both the upper and lower coolant hoses on the rad get hot, so I suspect that the thermostat is working fine, allowing water to circulate the system, but during this boil and settle scenario the warm air from the blowers inside turns cold, then turns hot again after the fan kicks in settling the water in the res back to normal level.
I popped in to see a couple of mechanics, both gave me different diagnosis, firstly that the thermostat might not be opening until too late causing the problem, and then after going to see an ex-rover garage I was told that it could just be the filler cap on the reservoir not sealing properly causing lost pressure in the system.

I've ordered a new thermostat this morning, I hope it isn't faulty because I hear it can be a right pain to replace on the 1.6's as it's round the back.

I've also temporary stolen my cap for the reservoir from my 420 and plonked it on the car, but as it's getting late and dark I won't find out till tomorrow's school run again if this has solved it.

Has anyone experienced this, or am I really being thick on this one and that it's just the header tank cap not sealing properly?

As I say, everything's been working grand so I hope this is just a silly thing!
Last edited by 2rovers on Sun Feb 26, 2012 10:01 pm, edited 1 time in total.
(M) Rover 420 sli saloon British racing green (show car) (walford.org)
51 v70 Volvo estate (200k and still ticking ) Daily driver & workhorse .
01 v70 Volvo estate (205k and is poorly )

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Re: Am I being a tit or am I missing something?

#2 Post by E_T_V » Tue Feb 21, 2012 6:08 pm

Both mechanics can be right. I'd also add to that to bleed the system as it needs to be filled slowly and properly to avoid getting airlocked.

(From a low coolant level undo the bleed point on the coolant rail near the distributor
Turn the heater dial to hot
Fill with coolant slowly until it starts coming out of the bleed point
Re-tighten the bleed point and fill slowly again till coolant is at the max level.
Start the engine and run until warm (you'll feel the thermostat open as the gauge gets near the middle of the scale and the radiator hose will get hot suddenly).
Top up as necessary then re-tighten the cap.
Eventually if left long enough at idle the temp will rise above the middle of the gauge and usually about 3/4's the way up the radiator fan will come on and the temperature should fall back to the middle of the gauge when it will turn off again.


If the gauge gets above about 3/4's without the fan coming on then I'd be concerned.
Equally if the cap doesn't seal the coolant will boil before it should causing coolant loss.

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Re: Am I being a tit or am I missing something?

#3 Post by 2rovers » Tue Feb 21, 2012 6:54 pm

Righty oh, well, I forgot to mention that I had been bleeding the system and seeing a clean jet of water coming out, I had topped up accordingly, but then thought that while topping up while hot will cause the system to be over filled, and what's been going on is that it's been forcing water out from the cap all down the rear of the engine.
Last edited by 2rovers on Tue Feb 21, 2012 7:20 pm, edited 1 time in total.
(M) Rover 420 sli saloon British racing green (show car) (walford.org)
51 v70 Volvo estate (200k and still ticking ) Daily driver & workhorse .
01 v70 Volvo estate (205k and is poorly )

2rovers
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Re: Am I being a tit or am I missing something?

#4 Post by 2rovers » Tue Feb 21, 2012 6:57 pm

I must have a keen sensor, as my fan doesn't kick in till temp hits a fraction below mid point, always been like that, same on my 2.0 t series, comes in early a fraction. I've never seen the temp raise above half even under its recent conditions.
(M) Rover 420 sli saloon British racing green (show car) (walford.org)
51 v70 Volvo estate (200k and still ticking ) Daily driver & workhorse .
01 v70 Volvo estate (205k and is poorly )

montygti
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Re: Am I being a tit or am I missing something?

#5 Post by montygti » Tue Feb 21, 2012 8:20 pm

If its not the thermastat i bet it just a typical rover air lock some where in the system. What i usually do is warm it up, once warm switch off and take the coolant tank cap off and just leave it for a few hours. Usually your here bubbles of air escaping as it cools. Dont always bleed the system just using the bleed screw take the temp sensor out as well. And always make sure the heater is turned on to hot.

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Re: Am I being a tit or am I missing something?

#6 Post by 2rovers » Tue Feb 21, 2012 8:29 pm

Alrighty then, i'l have a butchers tomorrow, I just hope it's a bit warmer than what today was, a tad fresh is an understatement, a clear day, bright, but a bit nippy on the extremities !

Needless to say, I bet rover were popular with such a convoluted idea :blink :blink :blink :blink :blink !


Cheers
(M) Rover 420 sli saloon British racing green (show car) (walford.org)
51 v70 Volvo estate (200k and still ticking ) Daily driver & workhorse .
01 v70 Volvo estate (205k and is poorly )

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Re: Am I being a tit or am I missing something?

#7 Post by E_T_V » Tue Feb 21, 2012 9:52 pm

You only need to bleed if the coolant level is low, i.e. when you are filling it up. If done properly during filling no futher action is necessary. No need to remove anything else when doing it either so long as the heater is set to hot (as this is where the biggest airlocks usually occur).

With a hot engine if you fill it up to the max level it'll only ever drop when it gets cold not get higher. The system is set up so that if you fill it to the max level when cold it'll be above the max level in use - this is perfectly normal and acceptable. That is why the max level is no-where near the top of the bottle - to allow the coolant to expand.

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Re: Am I being a tit or am I missing something?

#8 Post by 2rovers » Tue Feb 21, 2012 9:56 pm

cheers, il have a bash tomorrow then. fingers crossed all will be well.
(M) Rover 420 sli saloon British racing green (show car) (walford.org)
51 v70 Volvo estate (200k and still ticking ) Daily driver & workhorse .
01 v70 Volvo estate (205k and is poorly )

2rovers
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Re: Am I being a tit or am I missing something?

#9 Post by 2rovers » Fri Feb 24, 2012 1:08 pm

Ok folks, I had a butchers at the car yesterday, managed to get a little time to myself!!!!
I ran the car and removed the bleed screw to confirm I had no air coming through, whilst do that the screw decided to do a Houdini on me and pop out , buggered off under the pipe , so after getting a face almost full of water whilst trying to find the elusive thing, I turned engine off.
After finding it and repeating the process, I secured it and then topped up to the min on the header tank.
Sat there and waited, all the time having the blowers on warm, she started to get to temp when the fan kicked in accordingly.
At last I thought it was done.
Famous last words, and after a lot of erm, spirited driving ,as I had a lot to tend to , I could hear the fan kicking on even while I was driving on a clear road at a steady 65 and chilly out too.
The fans certainly coming on now, and I've replaced the header tank with another cap from my 420 so it's not leaking water now, but I still have the fan coming on while driving, even after a short distance on the school run this morning.
I haven't replaced the thermostat yet as I don't have time, need to go to Bristol this afternoon.
I'm starting to also consider that there's a possibility that the radiator might either be completely guffed or that it's got a blockage.
If it's not one thing it's another..... The story continues, darn temperamental thing!
I'l see how it fairs en-route later and get back to you.
Cheers for advice guys, il keep you informed . :-)
(M) Rover 420 sli saloon British racing green (show car) (walford.org)
51 v70 Volvo estate (200k and still ticking ) Daily driver & workhorse .
01 v70 Volvo estate (205k and is poorly )

2rovers
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Re: Am I being a tit or am I missing something?

#10 Post by 2rovers » Sat Feb 25, 2012 7:49 pm

Hi all.
Well my drive to Bristol did not bide well!, I got as far as Telford and started to get cold air coming through the blowers and a weird crackling noise coming from the header tank.
After many stops, roughly ten mins of driving at a time , I got back home, decided to call it quits for the night.
This morning I got out to have a look at what was going on, after spending 5 hours today , changing thermostat, removing radiator to check for flow and blockages, and removing most pipes to see which were getting coolant and which weren't,and constantly replacing lost coolant, I Still am stuck.
Basically I've removed the bleed screw and waited for said jet of water, I know the waters cycling through, as it's as clean as the water I'm putting in, after a while I was getting intermittent jets coming out, then it stopped completely! , I replaced the lost fluid in the header and replaced cap, after less than a minute the fan kicked in. There is warm water coming out the bottom hose, and there's heat on the rear hoses going through the bulkhead too.
I just can't figure out what's going on, all the time the blowers have been on, and briefly it was blowing some warm air, again with the rad fan staying on, I decided to take it for a quick spin, thinking I may rectified the issue, but after less than a minute driving the blowers again started venting cold air, the temp gauge sits at halfway point all the time.
The main coolant pipe that runs across the top of the rad was starting , or felt like it was hard, after squeezing it I couldn't feel any water, and yet at the header tank it was brimming, and making an awful crackling noise, almost blistering hot water forcing it's way out, after I let it cool for a short while I removed the header tank cap, and then I could hear water populating the system as it reduced and ran from the header tank.

I've replaced the water pump recently, now the thermostat ( which wasn't easy) I've checked the radiator, looks like it's seen better days, but holds water and let's water run through it ok, so now I'm at a loss....
Its almost as if there's a blockage, and pressure is building up a heck of a lot into the header tank causing this awful crackling noise, and swelling of the rad hoses, I am only losing water when the header tank is so full it bursts out !

And still no heat coming through consistently. Last night when I was driving the car, if, which I did, was to drop the clutch and let the engine idle, warm air would then come through the blowers, so I'm really hoping that I can eliminate the head gasket .
It's not the hardest job to be fair, but I just don't want to accept that it's gone with less than 10k on it!, and everything was working fine till the fresh spell we had a few weeks ago...

Sorry for long explanation....perhaps I've had a long day, but really cannot figure it out, it wasn't this difficult or stubborn when
I replaced the head last year, and certainly not 5 hours that's for sure
(M) Rover 420 sli saloon British racing green (show car) (walford.org)
51 v70 Volvo estate (200k and still ticking ) Daily driver & workhorse .
01 v70 Volvo estate (205k and is poorly )

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Re: Am I being stupid or am I missing something?

#11 Post by E_T_V » Mon Feb 27, 2012 9:40 pm

Once there is an airlock in the system you can't simply bleed it to get rid of it. You need to almost empty the coolant and start from scratch again.

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Re: Am I being stupid or am I missing something?

#12 Post by 2rovers » Tue Feb 28, 2012 12:15 am

Well, I can give it another try in a couple of days, although I was told it could be hgf or possibly a cracked head, venting or compressing air through a gap causing an air block to develop and as a result forcing coolant back to the header tank.
Last thing I need is a knackered head and at over 100 quid a time is not the kind of thing I wod look forward too.
It's not the worst job, just irritating to have to do.
Last resort would be to remove the head if it comes to it, then it's another gasket and maybe get the head pressure tested , 50 quid to do , plus another 50 for a skim! .
Need to get her back to normal, and i still don't understand what initially caused it :-(
(M) Rover 420 sli saloon British racing green (show car) (walford.org)
51 v70 Volvo estate (200k and still ticking ) Daily driver & workhorse .
01 v70 Volvo estate (205k and is poorly )

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Re: Am I being stupid or am I missing something?

#13 Post by 2rovers » Tue Mar 06, 2012 7:14 pm

Righty then guys,, I went to my local so-called ex rover dealership, and their information was about as much use as a glass hammer!!! I've spent the last week trying to figure out what on earth is going on, and am borderline ready to give up. Why oh why have rover ever decided to have such a convoluted system to bleed the coolant I really don't know, but after several attempts I am at a loss as to what to do with it, it was never this much hassle when I rebuilt the car last year, and I've had contradicting info from garages left, right and center and now it's starting to annoy me.
At one point I did have heat, now again I have nothing! the upper and lower rad pipes get hot, the fan kicks in, the thermostat works, the water pump has been replaced, things are starting to get very very annoying now, as for the life of me I cannot figure it out. I'm getting heat on the pipes going towards the bulkhead, but not actual heat going through to the heater matrix, stone cold inside, apart from a brief spell earlier, I'm still getting that annoying ridiculous crackling of boiling water noise coming from the header tank,, when the fan kicks in things settle down, but not for long, when I feel the upper pipes it feels as though there's no water in them and they feel swollen, after opening the header tank with what appears empty, all of a sudden water rams itself in and overspills all over the place.
After undoing the bleed screw I get an almighty blast of water which launches all over the place.
I've been told that it may not be hgf, but nonetheless a more frustrating air lock possible in the heater matrix.
So in rovers fantastic design idiocy they failed to provide a means of removing said airlock easily!

Any ideas guys, otherwise something's going to happen to her and it won't be pretty, cos I'm all out of patience :headbanging :headbanging
Last edited by 2rovers on Thu Mar 08, 2012 12:49 am, edited 1 time in total.
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01 v70 Volvo estate (205k and is poorly )

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Re: Am I being stupid or am I missing something?

#14 Post by Fatdave » Tue Mar 06, 2012 7:27 pm

have you replaced the valve to the heater matrix. the rubber inside perishes then the water takes the shortest route around the system bypassing the matrix leaving only cool water in it. only mention it cos i was talking to a guy the other day who had a similar issue with his mg zr and that sorted it.
JS Performance group buy silicone breather pipes for T series turbo
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Re: Am I being stupid or am I missing something?

#15 Post by 2rovers » Tue Mar 06, 2012 7:31 pm

Any ideas where I may find said device?
(M) Rover 420 sli saloon British racing green (show car) (walford.org)
51 v70 Volvo estate (200k and still ticking ) Daily driver & workhorse .
01 v70 Volvo estate (205k and is poorly )

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