Loss of coolant and head gaskets ......

[Laird Scooby]

The reason i asked Bob is because some garages are fond of putting the red (OAT) stuff in, regardless. In most engines pre-2000 the gaskets are susceptible to failure with the OAT stuff, including the head gasket.

ANother problem is that the Organic Acid Technology (OAT) antifreeze won't mix with ethylene glycol antifreeze and usually forms a gel, blocking various different waterways within the cooling system.

If all your heater hoses are intact in the area above where you found the puddle, i know there are some core plugs in that area. I've never had to do one on a red block but i believe they can and do fail, causing leaks.

Not sure what the popping noise is, difficult to say without hearing it.

[bob12]

Originally Posted by Laird Scooby

The reason i asked Bob is because some garages are fond of putting the red (OAT) stuff in, regardless. In most engines pre-2000 the gaskets are susceptible to failure with the OAT stuff, including the head gasket.

ANother problem is that the Organic Acid Technology (OAT) antifreeze won't mix with ethylene glycol antifreeze and usually forms a gel, blocking various different waterways within the cooling system.

If all your heater hoses are intact in the area above where you found the puddle, i know there are some core plugs in that area. I've never had to do one on a red block but i believe they can and do fail, causing leaks.

Not sure what the popping noise is, difficult to say without hearing it.

Thanks Dave. There's definitely no OAT's (wild or otherwise) been sown in the system.

I shall investigate further later tomorrow.

[bob12]

Well ... I had a prod (only on the breaker today) and only to remove the alternator in prep for fitting it to the 745. As invisaged having been left to lay for a couple of years it was a bit of a bugger to get out! It seems sweet though!!

BUT ... back to the the apparent leaky flexi coolant pipe somewhere on the backend of the 'working' 745. Whist removing the alternator there seem to be 2/3 flexible pipe around there. It's very difficult to see.

You have the flexi off the heater metal pipe, and what looks like 2 off the back end. Some years ago on the 'driver' one pipe went 'bong' in a cloud of steam over a hot engine, and whilst I haven't dug too deep so far because of lack of easy seeing .... how may flexi pipes are there around the backend and where do they go.

My many copies of Volvo 'Green Books' don't seem to provide a simple (!) schematic of the pipe work for a non a/c cooling system including the heater matrix.

Help please ... just a simple route guide sketch would be enough.

Have u seen the price of a new alternator 'CP4L' seem to be the best current buy at about £153 for a Bosch ... that's about what I paid for the breaker.

Bob

[Laird Scooby]

Couple of useful ideas for you Bob - first, get an old door mirror glass and use that to look under manifolds, behind heads and so on - it's amazing how much easier it makes things!
Alternatively if you have a phone with a camera, especially a flash on it, use that to take snapshots of what's happening or videos even.

The other idea is have a look on fleabay for chargeelectrical, based in Manchester they sell new, used, reconditioned alternators and starters.

https://www.ebay.co.uk/itm/VOLVO-740...IAAOSwAYtWOhen

That's the Nippon-Denso unit fitted to later turbo cars, yours is probably still a Bosch unit but a lot cheaper than ECP/CP4L/carpartssaver either way.

I got my 827 alternator from them, another forum member on here bought his alternator for a late Mk1 940 from them so if you need one, that's a couple of recommendations.

[bob12]

Thanks Dave ... just been 'orf-line' for a couple of hours while my mini laptop up-grades (via a separate drive as it doesn't have enough inbuilt capacity to cope!). That's what happens with a little Aldi Medion note pad! but it's really great, and has been around the world 3 times with me.

Thanks for the direct to the Denso alt .... so what it's an alt. First, I shall clean up the breaker alt, and see what happens, and where we go from there.

Yes, as to the cooling system pipeage, I have a mirror, but was hoping for a simplistic pencil sketch of the pipework to help when I look at it it all. The Volvo Green Books are so unclear as you have to turn from page to page!

[Laird Scooby]

My desktop did an upgrade the other day and downloaded 20GB of "new" Widows installation. Slowed my PC down horrendously!

The link to the Nippon Denso alternator was more for the seller than the unit itself Bob, i doubt that would fit your 740 if it's not a turbo. I also know there are several different Bosch alternators fitted to the 740, depending on spec and as i don't know what spec yours is, it would have been a shot in the dark anyway.

The idea was, as you know what spec your car is and can check the numbers on your unit, it would be easier for you to find the right one from there with that seller.

It's also possible the one on your breaker isn't as big an output as the one on your car and also where it's been sitting, the bearings it it have "Brunelled" so will be even noisier than what you've already got.

As for a schematic of the cooling circuit, there is usually one in the Haynes book of Fantasy - an apt nickname in this case as it's usually a LHD cooling circuit. The RHD is similar but not the same and certainly not mirror-image so it's not really a terrific amount of help!

I'll have a think overnight and try to remember the cooling circuit from my 740s, if i can (or at least a passable facsimile of it) I'll try and draw it out tomorrow for you.

[bob12]

I found one in a very old edition of Haynes for the 740/60!

[Laird Scooby]

That's handy Bob - for some reason i've got a mental block this morning! Does it say if it's for a LHD or RHD?

[loki_the_glt]

I bought a recon'ed Bosch 100 Amp from QX for £94 delivered last month.

[bob12]

Originally Posted by Laird Scooby

That's handy Bob - for some reason i've got a mental block this morning! Does it say if it's for a LHD or RHD?

No ... it's not very clear!!