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Burning oil
Posted: Sun Aug 18, 2024 9:39 pm
by radioactiveman
Hello everyone,
For a little while I’ve suspected my car may be burning oil. I don’t think it’s excessive (it’s passed two MOTs and no one’s mentioned excessive smoke) but it’s certainly there.
I find that plug 1 fouls up quite considerably, and also today after reattaching my HT leads in the wrong order, whilst sorting them out, I’ve noticed cylinder 1 makes very little difference to the running of the car

It makes some, but the others certainly make more! Interestingly it would run on two!
Anyway… I’m assuming it’s the rings given I get a bit of blue tinged smoke if I rev him up.
I guess I’m asking how long do I have? My car does very few miles, probably in the low hundreds each year. Should I start saving for a rebuild… 2-3k? Or just chillax until it stops running altogether.
Has anyone else been in a similar position. What did you do?
Re: Burning oil
Posted: Sun Aug 18, 2024 9:55 pm
by philthehill
I fitted a BMC silver seal short engine.
I would suggest that in the mean time you run the engine with hotter plugs.
I also recommend that you run it until you are forced to recon the engine or fit a good S/H unit.
Re: Burning oil
Posted: Sun Aug 18, 2024 10:19 pm
by radioactiveman
philthehill wrote: ↑Sun Aug 18, 2024 9:55 pm
I fitted a BMC silver seal short engine.
I would suggest that in the mean time you run the engine with hotter plugs.
I also recommend that you run it until you are forced to recon the engine or fit a good S/H unit.
This is what I did today, popped in the NGK 5s rather than 6s.
If anyone near Surrey has a decent engine rattling around taking up space I’d be most grateful

Re: Burning oil
Posted: Mon Aug 19, 2024 6:26 am
by oliver90owner
I would be investigating that cylinder. Starting with a dry and wet compression test, maybe a pressure leakage check.
Head removal might then indicate a remedy, depending on what is found. That cylinder may be badly worn, compared to the others or it might just be a case of re-ringing that piston.
One can’t tell at this point, but it is not likely to improve unless remedial action is taken.
Re: Burning oil
Posted: Mon Aug 19, 2024 11:55 am
by jaekl
One of mine did that when it was 12 years old. Never checked the compression but after cleaning the plug it would run smooth enough. The engine tear down revealed Number one piston had melted top and second rings creating a cavity on the side of the piston. No damage to the cylinder and was bored .010 over like the other three. Depending on the condition of the rest of the engine, an alternative approach is to replace the damaged piston and hone the cylinder to hold you over until you are ready for a full rebuild. Unless you find damage to the cylinder.
Re: Burning oil
Posted: Tue Aug 20, 2024 9:37 am
by radioactiveman
oliver90owner wrote: ↑Mon Aug 19, 2024 6:26 am
I would be investigating that cylinder. Starting with a dry and wet compression test, maybe a pressure leakage check.
Head removal might then indicate a remedy, depending on what is found. That cylinder may be badly worn, compared to the others or it might just be a case of re-ringing that piston.
One can’t tell at this point, but it is not likely to improve unless remedial action is taken.
Thank you! I will get myself a compression tester and have a look see.
I'm reasonably tempted to just take the head off and have a look. I've never done it before but I'm an enthusiastic amateur with a torque wrench, youtube and a couple of workshop manuals!
If we're assuming I was just taking an exploratory look without wanting to fix the issue (at this juncture), would I just take everything apart, have a look, pop on a new head gasket and put it all back together?
Re: Burning oil
Posted: Tue Aug 20, 2024 10:56 am
by oliver90owner
I wrote what I would do. PTH could also be giving the better advice in this instance.
I have been taking engines apart since before my teens. I’m now in my 76th year. I started with motor cycles and progressed to cars in my early 20s. My brother and I usually had a spare engine to swap in if one needed attention. I always try to diagnose a fault before stripping/changing anything.
I would suggest pics on here (comparing the fouled plug with the other three?) as a start. Results from the compression and/or leakage test, too, before starting to dismantle anything. There is a lot of good advice available from most on the forum.
There are three ways of losing compression up, down and across. The last does not appear to be an option, here.
Re: Burning oil
Posted: Tue Aug 20, 2024 11:13 am
by radioactiveman
oliver90owner wrote: ↑Tue Aug 20, 2024 10:56 am
I wrote what I would do. PTH could also be giving the better advice in this instance.
I have been taking engines apart since before my teens. I’m now in my 76th year. I started with motor cycles and progressed to cars in my early 20s. My brother and I usually had a spare engine to swap in if one needed attention. I always try to diagnose a fault before stripping/changing anything.
I would suggest pics on here (comparing the fouled plug with the other three?) as a start. Results from the compression and/or leakage test, too, before starting to dismantle anything. There is a lot of good advice available from most on the forum.
There are three ways of losing compression up, down and across. The last does not appear to be an option, here.
Thank you, good advice, I will do a compression test in the first instance and go from there

I will also take some picture of the fouled spark plugs.
This is probably a stupid question, but when people say to put a 'drop of oil' down the bores, do they mean literally a drop or more like a table spoon?
Re: Burning oil
Posted: Tue Aug 20, 2024 5:52 pm
by philthehill
A tablespoon of engine oil or a couple of squirts from the oil can.
Re: Burning oil
Posted: Thu Aug 22, 2024 7:21 pm
by radioactiveman
Hello again,
Good news and bad news. The good news is I’ve added compression testing as a string to my bow

Another tool in the arsenal! The bad news is the results… My readings were as follows:
Cylinder 1 Dry: 155 Wet: 187.5
Cylinder 2 Dry: 150 Wet: 170
Cylinder 3 Dry: 137.5 Wet: 155
Cylinder 4 Dry: 152.5 Wet: 160
TYIA
Re: Burning oil
Posted: Thu Aug 22, 2024 7:33 pm
by philthehill
Well you now know the compressions for each cylinder. Well done.
Unless you are prepared to strip and overhaul the engine I would still run the engine with the hotter plugs until you are ready to carry out an overhaul or replace the engine with a good known S/H unit or better.
Here is an engine I noticed for sale when collecting a good 1098cc rear axle case from the same seller.
https://www.ebay.co.uk/itm/116286976631 ... SwGTBmuLTa
The engine appeared to be in good order and it is reasonably priced and not too far from you to collect. He is open to offers.
From the same seller I also picked up a 1098cc block with good bores.
Re: Burning oil
Posted: Thu Aug 22, 2024 10:08 pm
by radioactiveman
philthehill wrote: ↑Thu Aug 22, 2024 7:33 pm
Well you now know the compressions for each cylinder. Well done.
Unless you are prepared to strip and overhaul the engine I would still run the engine with the hotter plugs until you are ready to carry out an overhaul or replace the engine with a good known S/H unit or better.
Here is an engine I noticed for sale when collecting a good 1098cc rear axle case from the same seller.
https://www.ebay.co.uk/itm/116286976631 ... SwGTBmuLTa
The engine appeared to be in good order and it is reasonably priced and not too far from you to collect. He is open to offers.
From the same seller I also picked up a 1098cc block with good bores.
Thanks for your response. As long as the compression doesn’t seem completely awful that’s something!
It’s funny you should mention that engine. I’d spotted that myself and had been going back and forth with the seller, I’d asked what sort of ‘reconditioning’ it had had and he said “
the engine has been reconditioned with new piston rings, new main bearing shells and the connecting rod big end bearing shells have been changed. The block has got a cylinder head which is not fitted but ready to attach and included in the price”
Obviously you can never tell on eBay, but it seems possibly worth a punt.
Re: Burning oil
Posted: Fri Aug 23, 2024 8:48 am
by philthehill
I would suggest it is worth a punt.
The seller is a retired motor engineer and having talked with him I would say that what has been done to the 1098cc engine will have been done well.
The axle I bought had been well prepared and the shiny surfaces coated in grease so well pleased with that purchase.
The 1098cc block was also well preserved with lots of grease down the bores.
All of the parts for sale are only for sale as he is emigrating so it all has to go.
Re: Burning oil
Posted: Fri Aug 23, 2024 12:43 pm
by radioactiveman
philthehill wrote: ↑Fri Aug 23, 2024 8:48 am
I would suggest it is worth a punt.
The seller is a retired motor engineer and having talked with him I would say that what has been done to the 1098cc engine will have been done well.
The axle I bought had been well prepared and the shiny surfaces coated in grease so well pleased with that purchase.
The 1098cc block was also well preserved with lots of grease down the bores.
All of the parts for sale are only for sale as he is emigrating so it all has to go.
Ah, thank you for the extra information. Well, a punt I have taken

Re: Burning oil
Posted: Fri Aug 23, 2024 2:04 pm
by svenedin
My engine burns oil and leaks oil. It has good and consistent compression (170 psi all cylinders). I think perhaps oil control rings. The oil consumption is unsustainable at 1 Imperial pint per 100 miles so on a round trip to Germany of 1,000 miles it was rather expensive in oil. I have no real experience with engines and no space in the garage for taking engines apart so I am going to bite the bullet, take the engine out and have it professionally rebuilt. For me having the original engine with number matching the Historic Vehicle certificate is very important so an exchange engine is not an option. The original engine and I have far too much history together as well (35 years).
Stephen
Re: Burning oil
Posted: Fri Aug 23, 2024 2:47 pm
by mobylette
Make sure you take off and retain the engine number plate, often lost when the block is skimmed.
Re: Burning oil
Posted: Fri Aug 23, 2024 3:50 pm
by radioactiveman
svenedin wrote: ↑Fri Aug 23, 2024 2:04 pm
My engine burns oil and leaks oil. It has good and consistent compression (170 psi all cylinders). I think perhaps oil control rings. The oil consumption is unsustainable at 1 Imperial pint per 100 miles so on a round trip to Germany of 1,000 miles it was rather expensive in oil. I have no real experience with engines and no space in the garage for taking engines apart so I am going to bite the bullet, take the engine out and have it professionally rebuilt. For me having the original engine with number matching the Historic Vehicle certificate is very important so an exchange engine is not an option. The original engine and I have far too much history together as well (35 years).
Stephen
I think if I'd had 35 years with my car then I'd probably be thinking the same way you are!
Re: Burning oil
Posted: Fri Aug 23, 2024 4:13 pm
by svenedin
mobylette wrote: ↑Fri Aug 23, 2024 2:47 pm
Make sure you take off and retain the engine number plate, often lost when the block is skimmed.
Yes! I believe the plate is held on with screw-rivets (Scrivets) but I am not sure how to get those out.....
Stephen
Re: Burning oil
Posted: Fri Aug 23, 2024 4:55 pm
by mobylette
Sharp chisel should do it, or file their heads off (ouch!)
Re: Burning oil
Posted: Fri Aug 23, 2024 7:07 pm
by radioactiveman
Could the engine number not be transferred in that case? It feels like it shouldn’t be allowed.