740SE Estate - is it worth getting the head done?
 

Hi - I have a 1989 740 SE Estate with 107K that I have owned since '91 which has (I think) head gasket issues.
There is no water getting into the oil but I reckon there is into the cylinder. I can see white residue at the front of the engine down the left of the block. Steam comes from the exhaust occasionally once warm and it was overheating after about 15 miles. It needs coolant regularly. I have used 2x Steel Seal with limited success so don't want to go further with that so as to protect the waterways etc.
Overall the condition is not bad aside from..... headlining fabric rotting, fuel gauge not working, electric sunroof jammed (hey ho!) and driving lights fuse holder melted. MOT OK and expecting another pass in Dec.
Given I am not confident anymore in DIY car repairs, is it worth getting a mechanic to fix the head problem? If so, cost estimate? and where should I start to look for a suitable mechanic. Naturally not looking to pay huge sums!!Location near Heathrow.
p.s. I am not worried about the other issues; just whether it's worth getting the head done as I read the models are getting rarer.

Hello,

First. It sounds like head gasket but forum members might talk with you about checking the diagnosis. One useful check. Ask a garage to use their emissions tester to "sniff" the coolant header tank for exhaust gas.

You do not mention any corrosion and that in my opinion is fundamental to whether to repair a car. I still DIY and I am pleased that I did the head gasket on my 240. At this age, a car is entitled to the quite minor issues you mention.

Garage quotes will vary. Sorry. That is not very helpful.

But. I reckon your car's value is going up, at least to some degree. Your neighbour's car is on the way to shredded metal already ...... ;)


P.S. Whatever quote you get. The garage might find the head needs machining and possibly welding. But I would still get the job done. The way I look at it, the car is doing the job. One knows its little niggles &c. It is tough and will soldier on and hold or increase its value. If one gives up on it and buys another car, one is quite possibly buying someone else's troubles. How does the cost of repair compare to the cost of changing AND the depreciation of another car?


.

740 values are going up, but slowly unless it's a desirable model like a turbo :)

That said, the car can't have done you too badly if you've owned it since 1991.

Personally, I'd keep it - the repair costs shouldn't be too great and for a similar (or greater) amount of money you're unlikely to get another car you'd want to keep for 27 years :)

Oh yes. I missed that it was adopted in 1991. It's part of the family. :)

What he said! ^^^^^ I would, if you are now not so able to do it yourself, find a recommended Volvo indy in your area and get them to do a diagnosis. It could be the water pump, the short hose between the water pump and head or maybe the head gasket. If it's lost a lot of power and smoothness, suspect the headgasket - if not, suspect something else.

If the indy does find the fault, once they've repaired it, get them to do a heavy duty cooling system flush, fit a new thermostat and refill with ethylene glycol antifreeze - NOT the horrible red OAT stuff.

The idea of splashing out on an hours diagnostic labour is it will give you the knowledge to make an informed decision, whether to have it fixed if it's something minor, find a replacement head and get it fitted with a new gasket or have the existing head skimmed and a new gasket fitted if it's the head gasket or other head trouble or whatever else.

At the moment the answer is hidden in a dark forest full of black bears that will bite you and you're looking for the answer with sunglasses on - and it's the middle of a moonless night!

In other words, you're trying to second guess the problem - you need to have the problem diagnosed so you know what you're dealing with.

Probably best to have it repaired and keep it, after all, you know all its little foibles etc and buying another car could be one that's been patched long enough to sell it and you'd buy a cart-load of trouble. ;) :D

David is not wrong on this occasion. ;)

What is a heavy duty coolant flush? I am sorry I do not know. Every coolant flush should involve the block drain tap, and preferably a hose pipe. But? What is heavy duty flush?

the answer is hidden in a dark forest full of black bears that will bite you and you're looking for the answer with sunglasses on - and it's the middle of a moonless night!

Nicely put.

I agree with 'Laird Scooby' and 'Stephen Edwin', 'whittonwanderer'. Both offer sound advice. Sentiment aside, corrosion, or the lack of it, is key to the decision. Unlike more modern cars, a bodily sound 7 series can often be mechanically repaired, both effectively and (usually) quite economically. Although, as has been said, values are at last nudging upwards, the cars are still so reasonable to buy that you would be unlikely to recover the cost of any significant repairs.

Regards, John.

That sounds like the head gasket,
but the very good news is you've recognised it before any serious failure causes major overheating,
meaning the chance of a warped head is small,
meaning a removal of head, new head gasket, immediate refit of head in-situ (without sending off the head for a skim, my whole point) is likely to result in a cured vehicle,
with a good check/replace of water and oil hoses in any case.

A "sniff" test shouldn't cost much as it's not a long job.If it turns out to be H/G[or really any other job]that you can't cope with yourself are there no mechanically savvy forum members within reach of you that could/would take on the job in exchange for beer tokens?

I’d absolutely have it done. Considering the car has given you 27yrs of service and could well provide you with 27 more given the right care and maintenance (all the niggles you mentioned are sortable!), a head gasket is a small price to pay.

If it was me, I’d have the valves lapped in, new hushers and clearances set whilst I was at it, a top end rebuild as it were. It would be worth compression testing the cylinders too, that way if you need piston rings and a bore hone it can be done as an all-in job which will save you time and effort at a later date.

These cars are becoming less common and more desirable as has been stated...above all though, they’re a practical, handsome and reliable motor which is better built than a huge amount of cars being churned out today.

I had a three hour journey to make for work last night, in the howling wind and lashing rain. On my way I passed one 16 plate and one 17 plate car, both on the verge with hazards on a few miles apart, and one 18 plate car on the back of a recovery truck...I serenely motored past in my 28yr old 740 saloon and thoroughly enjoyed my journey!