Hi all I have been working my way through the suspension, brakes, fuel lines etc and now the engine on my S2 that has been stored for nearly 20 years. I took it for it’s first proper run today with a view to booking the MOT next week
Car was near perfect considering but on checking afterwards I have noticed rusty water marks down the side of the block.
I had flushed the system about 3 times but I guess there will always be an element left in the block somewhere. Anyway can someone confirm my worst fears that this is the head gasket gone.
Are you saying the rust dribbles were not there before you took your first proper run?
What sort of coolant are you using, 50/50 antifreeze and distilled water, or straight tap water?
You can retorque the head nuts, using the proper value and proper order.
Let it idle awhile and watch for more leaks.
It certainly looks like the HG is leaking.
Try a retorque.
If it’s a manual you can check for a leak with compressed air:
Make up a fitting with a sparkplug thread on one end, and compressed air on the other.
Fill the cooling system.
Rotate the cyls to TDC one by one
Leave the car in gear set the HB and block the wheels.
Feed that cyl with compressed air.
Watch for bubbles at the radiator cap.
If pressure from the combustion chamber reaches the coolant you’ve got either a crack, or the HG is gone.
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Are you loosing coolant, Graham - that must be patiently checked over time, with the engine cold…
Observe the level cold, using a reference point, after each drive - do not refill. With loss of coolant, you have a leak - and an external leak may be rectified by a retorque, as suggested by Rob and Andrew. When retorqueing; back of each nut half a turn, then torque to the correct value - one nut at a time in the prescribed torque sequence. Do not(!!) overtorque - it is not a solution to a head gasket leak…
With an internal leak; a compression test is necessary - which will also reveal the general state of the engine. You may also fill up the cooling system and run the engine with filler cap off. After some initial bubbling the fluid will just expand and slowly overflow as the engine warms up. Heavy bubbling and foul smell indicates a head gasket leak - as will hefty overflow…
It’s an auto but I guess I can still test as you suggested.
I didn’t mention that i replaced the cylinder head nuts for new chrome ones when I was cleaning the engine, whilst doing that 3 of the studs came loose instead of the nut so I replaced them. Whilst screwing one of them in you could feel some resistance from the bottom. I presume now this is dried rust, however everything torqued up ok so I left it at that.
Looks like I should have had the core plugs out and flushed it properly from below.
I will try the re torque today but they shouldn’t have moved after a 30 miles run should they?
The engine will try to turn when you apply the compressed air, your torque converter means that the engine can turn. This test relies on the piston being at TDC so that the pressure is only in the combustion chamber. You can try it, but I think you’re not going to have any luck.
Did you remove the stud nuts individually, or did you loosen them all off at the same time?
With a new gasket the heat cycle compresses the gasket between the head and the block, so you’ll get some motion when you cold retorque. Mark the D washers and nuts on one flat with a sharpie or paint pen, then loosen 3/4 turn and retorque them one at a time in the order shown in the shop manual. You can tell if there has been any motion by looking at how far your witness marks move. With a fresh composite gasket you’ll get something like 1/8 turn after the first heat cycle, but after 2 heat cycles the witness marks should come back inline with each other.
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If the studs are not fully seated in the block, Graham - they will stand too proud of the head. Using acorn nuts this will then ‘bottom’ the nut - and the torque reading will be the twisting of the stud. ‘Proper’ torque readings is the friction between the nut, the head and the stud thread…
So if you have committed this error; retorquing is pointless without rectifying the problem. You may try and verify the clearances of the replaced studs by measuring their protrusion against the hollow in the acorns. And compare results with the ‘unsuspected’ studs - the clearances are not specified, but some 1/8" may be in the ballpark…?
If indeed this is the problem, you have 3 options. The correct one of clearing the block threads as you mentioned. Then…
…unless the protrusion of the studs are excessive, implying that there is too little ‘hold’ in the block threads; one alternative is to use simple ‘open’ nuts. Not pretty, considering you probably changed the nuts for aesthetic reasons. You may, however, use this solution as a verification that proper torqueing will solve the leak - then take the ‘proper’ steps…
…or, again if the bottom threads are deemed secure, use washers of suitable thickness to obtain required clearances…
Grinding off the top of the offending studs enough to obtain required acorn clearances will compromise later proper repairs, not advisable. Do not remove studs from the engine, which may aggravate the ‘bottoming’ situation - unless the block threads are to be cleaned…
Lack of proper torqueing will compromise head gasket integrity - it will eventually fail completely internally. The possible external leaking is just a warning sign…
Thought i’ll give you an update, I took the head off today to see what I could find. Nothing seemed too bad until I took the core plugs out and wow, even after flushing with the correct stuff 3 time I found this !
I’m now going to get the head skimmed,flush like crazy and replace the bolts and gasket. The Rad seems fine is there anyway to check before spending money getting it recored just in case.
When this goes back together I never want it out again! So any advice now would be appreciated.
…‘flush like crazy’ with the core plugs out seems like a good start. You have ‘reverse flushed’ the radiator, I guess, but there is no specs given for the flow - and if the insides of the engine looks like that, one wonders what got into the radiator.
But I would not skim the head unless it is proved necessary by measured warping - mating surfaces damage…
I suggest you take the plate off the rear of the engine block off too. It’s held on by 7 or 8 bolts and opens into the water ways of the block. You’re very likely to find more congealed goop there too. You’ll need replacement gasket when refitting.
Regards,
Andy
I was about to write and answer - yes it can certainly be done on an EFI Series 3 with the engine in the car working from the exhaust side of the engine - but then considered that I have a RHD car with no AC. LHD may make a difference maybe someone else can comment.
It’s certainly easier with at least one of the heater matrix hoses out of the way.
As the original lister owns a ‘Sovereign’ and refers to an MOT test I’m guessing he’s based in the UK, I can’t think what there would be on a RHD Series 2 that would make it any more difficult than on a Series 3.
Should be easier with the cylinder head removed too.
The bolts that hold it in are only 1/2" long so don’t need much space as they unscrew out of the block before they are free.
On refitting the issue you will have is crud in the head stud threads - this must be removed otherwise the threads will not bottom and the studs will be too proud to seat and tension the dome nuts. Have seen additional washers to accommodate per Frank above. I used a 7/16 unf tap welded to a long “T” bar that comes to beyond the block deck. Repeatedly bottoming the tap brings up the crud. New studs with sealant and Bob’s your uncle. Good luck. Paul
Yes, you can never pull a long stud in situ, as the crud falls into the hole, and prevents the stud bottoming out well enough to hold torque. Its a shame the only way to find this out is the hard way, or via a forum like this.
Thanks for the advice, I suspect that was the problem in the first place when I originally changed the nuts, 3 studs came out and the crud fell to the bottom.
I haven’t taken the studs out yet for that very reason except the two that came out as I undid the chrome nuts
I spent an hour or more cleaning the crud out with a long screwdriver and an air gun, it was unbelievable what came out, I will continue tomorrow when it’s complete dried out and flaking.
Should I leave well alone with the existing studs or replace them all. I did make sure they were all free by undoing 1/8 of a turn, but I don’t want to give myself more problems to fix.
Also should I somehow pour some acid cleaner down the bore holes and flush it out, I’m a bit nervous of getting water down the cylinders. Even with paper towels, rags and cling film over them.
