Rover 75/MG ZT coolant level mystery.

[Bobthebeard]

Possibly one for the stupid question thread, but got me puzzled.

Both of my cars have similar symptoms. The coolant level in the expansion tank. Checking when cold the level is at the Max mark sometimes, then way below at other times. Without adding any coolant. Occasionally both cars will burp a spoonful or so of coolant out of the cap onto the expansion tank top when hot. Have fitted new OEM caps to both cars expansion tanks but still the same. No overheating in either car even in heavy traffic. Do 'they all do that sir', or is something amiss? No major loss of coolant at all. Releasing the cap on either car when stone cold results in a gurgle/hiss and the level returns to normal ish from very low.

Possible paranoia, but just seems odd! Especially the burping out of coolant from the cap even when the level seems low.....

[Barry Cade]

KV6's are a bloody nightmare to bleed. follow the offishul proceedure to the letter or beg,borrow or steal a vaccum filler. Either way they'll still belch for a bit,then settle down.

[cdwood2010]

I had an MR2 do something very similar to me recently. It turned out to be the top on the expansion bottle, which was fitted the wrong way around, and it would allow coolant in but not back again.

 

Check the expansion plumbing, make sure it's doing what it should be.

 

Chris.

 

Sent from my Pixel XL so I'm probably on the loo.

[Bobthebeard]

Thanks Barry! Was hoping you were still awake! ðŸ˜

Assume the issue just long standing airlocks then?

[Barry Cade]

pretty much- as long as they don't run hot, or lose coolant, just keep doing what you're doing and they'll settle. I assume heater is hot etc?

 

What's this 75 you#ve got? missed that one!

[Bobthebeard]

Yep... heater hot on both cars. Same symptoms on both. Both have had timing belts changed and water pumps. I didn't bleed the cooling system on the MG after the pump change. Just topped up. Possibly the same thing happened on the Rover, although I wasn't involved in that.

[Barry Cade]

remove bleed screw from bottom hose (this looks to be to the left hand side of the air cleaner box)
Release expansion tank bleed hose from clip
on top hose.(small diameter hose coming from the neck of the tank)
Remove bolt securing expansion tank and
release tank from location in radiator.
With assistance, raise expansion tank to
maximum height hoses will allow
(approximately 125 mm).
CAUTION: When raising the expansion
tank, ensure that the plastic hoses do not
become kinked.
Fill cooling system, keeping coolant to neck of
expansion tank until a steady stream of coolant
is emitted from bottom hose bleed screw hole,
then fit and tighten bleed screw.
With expansion tank still raised, continue filling
until coolant reaches expansion tank neck and
remains static.
Lower expansion tank and locate to radiator, fit
bolt and tighten to 5 Nm.
refit expansion tank bleed hose in clip on
top hose.
Models with A/C: Ensure air conditioning is
switched off.
With expansion tank cap off, start and run
engine, at 1500 – 2500 rev/min. Fill expansion
tank as necessary to maintain coolant level just
below expansion tank neck. When coolant
starts to rise up expansion tank neck, due to
heat expansion, fit expansion tank cap.
Continue running engine at 1500 – 2500 rev/
min until cooling fan comes on, then run engine
at idle speed until cooling fan stops.
Switch off engine and allow to cool for 30
minutes.
Check cooling system for leaks.
Remove expansion tank cap and, if necessary,
top-up coolant to MAX level. If MAX mark is not
visible, remove excess coolant until level is at
MAX MARK.
Refit expansion tank cap.

[Bobthebeard]

The Rover 75?

This one...

Now registered as G10 SAT...

 

[Roverageous]

Mine has done the same. Bled it properly and it's been fine since. Has never run hot & always had hot air through heater.

 

Checking the level in these is just a complete pita anyway!

 

Sent from my Pixel using Tapatalk

[eddyramrod]

Is that ZT the ex-Chompysnake one?

[EssDeeWon]

Lovely 75 there Bob, is there a thread or more pics of this?

 

Regarding the coolant and bleeding the system, well I am no expert but I know when I had my belts and thermostat housing all replaced it took the garage ages to get the system bled and settled, the bloke worked quite late to get it done, and his a well experienced MG Rover mechanic.  

 

I think you need to take the expansion tank off and keep it raised.

[Bobthebeard]

Is that ZT the ex-Chompysnake one?

Indeed it is Eddy.

[oldcars]

That's a really nice driveway. Cars are great too 

[AMC Rebel]

+1 for the bleeding bleeding.  Mine has always been a total bastard.  I wonder how they came up with such a difficult to use design?  I suspect it was because they had to use the BMW tank and cap.  

 

I regard the "clever" BMW electronics for the temp gauge to be one of the stupidest designs of all time.  Imagine if your fuel gauge stayed bang in the centre between 1/4 and 3/4 full. 

[Bobthebeard]

+1 for the bleeding bleeding. Mine has always been a total bastard. I wonder how they came up with such a difficult to use design? I suspect it was because they had to use the BMW tank and cap.

 

I regard the "clever" BMW electronics for the temp gauge to be one of the stupidest designs of all time. Imagine if your fuel gauge stayed bang in the centre between 1/4 and 3/4 full.

 

Indeed so....

Although it does give the cars "character" I suppose!

They do require a lot of looking after and are fairly needy IMHO, which is why so many survivors are riddled with problems. People often just don't look after them or give them the attention they need. Still, it means they are becoming rarer in good condition I suppose, the bad ones are disappearing. The Rover has had a caring previous owner and will continue to be pampered. The MG is nicknamed 'Warrior' for a reason.... It has survived a few battles before my tenure but lives to fight another day and is now likewise pampered. Although the MG has cost £££££'s to repair the battle damage/restore.

[AMC Rebel]

He he - I fell out with a few folks on the Rover forum about "looking after" mine.  I bought a low mileage car from a Forum member at considerable expense.  It had a full history and had been looked after with a lot of recent work.

 

After I had it a while and had lavished loads of care and cash on it it had OMGHGF - I honestly cannot see how I could have done more to avoid it, but to the die-hards on there, the fact I didn't change the oil every day and renew the air in all the tyres after each trip was proof it was all my fault.

[Bobthebeard]

Lol....

I was speaking generally.. Some cars are just ungrateful bastards.

[Barry Cade]

He he - I fell out with a few folks on the Rover forum about "looking after" mine.  I bought a low mileage car from a Forum member at considerable expense.  It had a full history and had been looked after with a lot of recent work.

 

After I had it a while and had lavished loads of care and cash on it it had OMGHGF - I honestly cannot see how I could have done more to avoid it, but to the die-hards on there, the fact I didn't change the oil every day and renew the air in all the tyres after each trip was proof it was all my fault.

I don't even dare consider expressing an opinion over there. Place is nuts!

[Bobthebeard]

They are worth it though... I think...

I love 'em.

 

[Bren]

I always check to see how high up ( compared to engine)the expansion bottle is - fiesta zetecs are a PITA to bleed - I ended up lifting the expansion bottle up - it did the trick.

[Bobthebeard]

I always check to see how high up ( compared to engine)the expansion bottle is - fiesta zetecs are a PITA to bleed - I ended up lifting the expansion bottle up - it did the trick.

Expansion tank lifting will occur soon. The only way seemingly.

[AMC Rebel]

.....r beg,borrow or steal a vaccum filler. ....

 

How do these work? I have a mityvac I might be able to use (will be filling mine again soon).

[Guest Hooli]

 

 

I regard the "clever" BMW electronics for the temp gauge to be one of the stupidest designs of all time.  Imagine if your fuel gauge stayed bang in the centre between 1/4 and 3/4 full. 

 

Seen the same thing on a '58 festering gauge. Hence the 20k lump having OMGHGF before it bothered to tell anyone it was getting warm.

[eddyramrod]

Indeed it is Eddy.

Aha, I wondered where it had gone, thank you

No real reason btw, just, I like to keep track of my old cars if possible.

[Eddie Honda]

Rather than raise the tank, could you not take the PSA approach to burping a system where the expansion bottle isn't the highest part of the system?

 

 

By attaching a 2L plastic bottle fitted to an old cap and filling this to the top.

 

 

The higher column of water should do the trick??

 

I might be talking bollocks though.

[Barry Cade]

Gripe water. Or sling it over your shoulder and pat it's bonnet.. just do what works to get a burp.. just don't ask in the other place without a flack jacket and tin helmet..

[oldcars]

These seem almost as much hassle to bleed as the Rialto with no header tank. Took ages to get the airlock out.

[Barry Cade]

These seem almost as much hassle to bleed as the Rialto with no header tank. Took ages to get the airlock out.

Try an X1/9 !

[BorniteIdentity]

Although it does give the cars "character" I suppose!

 

 

Exactly this.  I think I said here (or on PH - boo hiss) that they were the last ever mass manufactured car to be produced that still require looking after, and still have idiosyncrasies.  I think it's what makes them rewarding to own.

 

The coolant level on my v6 (as Essdeewon will testify) regularly made poo come out of my bottom.  In reality, it was absolutely bloody fine.

 

Lovely car.  Try not to let the shortcomings spoil your enjoyment of what is a fantastic car.

[Roverageous]

Exactly this.  I think I said here (or on PH - boo hiss) that they were the last ever mass manufactured car to be produced that still require looking after, and still have idiosyncrasies.  I think it's what makes them rewarding to own.

 

The coolant level on my v6 (as Essdeewon will testify) regularly made poo come out of my bottom.  In reality, it was absolutely bloody fine.

 

Lovely car.  Try not to let the shortcomings spoil your enjoyment of what is a fantastic car.

 

Exactly.

 

Having said that they HAVE lasted bloody well. I think they're pretty hardy but let down by some little niggles which in turn can create big problems - especially around the K series engine.

 

I've owned 9 75s in the past few years, and had engines of all flavours - They're the only model of car I've owned that I've never had a breakdown / FTP in.