cliff.b

Just reading this as today I had to free up pistons in the OEM calipers I bought less than 2 years ago from a "well known supplier". This is the 3rd time I have had to do this and I have zero confidence I won't need to do it again before very long. So I am thinking about what to do when that happens. I still have the original calipers, each with a seized piston, but I haven't tried very hard to free them. Initially, I was thinking I would just exchange them for a refurbished pair but reading the above, wondering if I should try doing this myself. But are the kits available to buy any better than the parts in the OEM calipers. Are some known to be better than others? If the refurbishment kits are acceptable quality, is there any reason why I shouldn't use them in the newer OEM caliper bodies? Has anybody done this?

👍

I am certainly going to check out the PRV. I haven't checked the distributor end float but once set, is this something that can change? The noise has only recently become obvious. Guess it's something else I can check.

I asked specifically if they thought it might be that and they said it didn't obviously sound like it but couldn't be certain without taking the sump off.

Just a further update, the noise was apparent today and as I was close to a well known classic vehicle restoration company I took it in and asked if they would have a listen. Other than agreeing that the noise seems to be coming from the middle of the engine block, they seemed as confused by it as I am. They did say they could fit the car in to investigate further in maybe 3 months though. Interestingly, they are working on another Spitfire which the mechanic said was a LeMans racing car.

Yes, it makes sense to just clean them. I had tried to resolve what I believed was a pad sticking but now I have dismantled again I can see that it was the piston in the OEM caliper I fitted just over a year ago. Freed it up but not happy it happened

When I last attended to my front brakes I applied copperslip to the pad retaining pins but on stripping down again today, it seems to have mixed with road dirt to make a sticky gunge, which is probably the opposite of what I had intended. Just wondered if other people just fit them clean or use anything different?

I will report back with my observations when I get around to changing it. Meanwhile, I will have to remember to drive more sedately 🥱

Yes, Castrol Classic which I believe is marketed as being as good as it always has been. Also, to prove its heritage, I presume, they sell it by the gallon, which as we all know is less than the 5 litres the can holds lol.

Yes, been looking at the various options and thought this might be worth a try. Interested in any opinions

I'm thinking that once I have eliminated the other things, I might try an earlier suggestion and change to a different oil. If it helps then at least it will confirm that it is oil related. Just have to decide which one is most likely to be of a benefit in this situation. Only having an issue when driven hard.

Certainly worth checking out.

I presume fitting the cooler sorted out your oil issues. Had you tried using any other oils first?

Ok, I know where it is but misunderstood it's purpose. Definitely worth a look 👍

Ok, I have given details of the driving I have been doing as the oils pressure drops depending on how I drive it. The worst it gets, after sustained high speed or enthusiastic back road driving, is about 10psi per 1000RPM with 10psi at tickover. If I drive more gently it stays at about 15psi per 1000RPM & tickover. So I am assuming the difference is that the oil is getting hotter, which is sort of supported by the temp of the oil filter being higher when I got the noise. But now I have refitted the fan the water temp seems ok ,with the return at only 60C yesterday. Can the oil temperature rise when the water temp doesn't? Is this the rationale behind oil coolers? Not saying I need one, just wondering why people have them.

When you say the oil pressure regulator, do you mean the filter bypass? When cold I am getting 65/70 psi so if that was stuck open, wouldn't the pressure be low then as well?

Probably about 1500RPM and then pressure (when hot) of 10 to 15 psi

Part 2, Friday 10th Another drive out today and the only thing I had changed was to turn the fan thermostat down to 70C. I had also brought my IR thermometer thing and my new mechanics stethoscope. As the previous week, 20 odd miles up the A1 to the meet point then a gentle drive 30 miles across country in convoy. When we stopped I couldn't really hear anything unusual and neither could anyone else. The fans hadn't come on at any point but it was a fairly chilly day, about 8C. I pointed the thermometer thingy at the top of the oil filter and it read about 95C. Does that sound normal for this sort of lazy driving. Becoming more convince it's temp related. Anyway, during last week I refitted the mechanical fan and also replaced the front number plate with a much smaller one to hopefully improve airflow. Another drive out yesterday 17th (to the club HQ which opened on a Friday just for us 👍) and this time the weather was warmer (15C), we were driving faster but when we stopped the top of the oil filter only showed 85C & no discernable noise. Drove non stop all the way back, briskly on the A47 then South on the A1 before turning off to cover the last 10 miles cross country. This is bendy almost empty B road and I drove it pretty much as fast as I could. Car felt great, no sign of any problems until I stopped just before home, opened the bonnet and the noise was back the same as before. My best guess with the stethoscope is the bottom middle of the block, almost as much a vibration as a noise, can't hear it when I increase revs. Oil pressure gauge at this point showing a fraction under 10psi at 800RPM tickover, top of oil filter showing about 100C on the IR thermometer. Maybe I just need to stop driving it like this 😟

Ok, further updates on this matter. I previously explained that after a drive out on Fri 3rd everything had seemed fine until I "put my foot down" on the way home. The following week I started checking things out and noticed the electric fan thermostat, which is in the radiator return pipe, had been turned up to 90C. (I blame small grandchildren who had the opportunity and past form on this sort of thing). Usually, the mech fan is fitted and the electrics just retained as a backup, but as it had been so cold I removed it to speed warm up. Anyway, during the trip on the 3rd the fans had come on in traffic so at some point, the radiator return temp must have been 90C+ and I started becoming more convinced this was a heat problem. Part 2 to follow

I am going to have to put further investigation on hold for a bit as too busy but plan to start from scratch and methodically look at all possibilities discussed here. I can live with a loose nut lol

I have heard that elsewhere. When the noise is there, as far as I can tell it does seem to be coming from the lower rear of the engine.

Will do 👍

After reading up on the various options I used Dynax last year and certainly found it easy to apply using the aerosol and wand supplied. Insert fully through a drain hole into say a sill, then withdraw it while spraying. Time will tell if it is effective but the description of how it works makes sense. I'm sure it said it's used on oil rigs 🤔

Many thanks.

As you say, many ideas and I appreciate all of them 👍 I will work through it all, easiest things first.