04-08-2019, 10:49 PM
It being a fairly dismal afternoon here in Bala, and having taken delivery of a 1/4 BSF Helicoil set this week, I thought I would tackle my manifold studs.
I have been troubled ('plagued' is too strong a word) by niggling manifold problems ever since I bought FG in October last year. The first thing that I noticed was that one of the manifold studs at the rear had broken off, so , when I had the engine out to reline the clutch, I removed the manifold and drilled out the broken piece, re-threaded it and fitted a complete set of new studs. I noticed then that one or two of the block threads were a bit weak, but the new studs went in OK and appeared snug.
Then, one morning whilst I was on my way to Llangollen, one of the manifold studs came out and decanted the coolant all over the A5. Fortunately, the stud was lying on the side tray between the engine and the flitch plate, so it was jammed into its hole having wrapped the end with a piece of paper. Water was begged from a nearby house and I went on my way. A more permanent repair was effected when I got home using some 'magic' plumbers sealant that sets under water but I knew that I would have to deal with it eventually and so the problem was put on the (ever growing) list of things to be attended to when the car comes off the road this winter.
However, more recently, I have noticed a 'whicker' from the manifold on cold starts that goes away as the engine warms up, together with a tendency for the car to backfire on the overrun. Suspecting the manifold gasket, I ordered a new one and the aforementioned Helicoil kit to deal with any weak stud threads.
The original plan was to order an new exhaust system and do the manifold and exhaust at the same time, but given the difficulties already reported on this forum concerning exhaust system supplies, and, given that, in consequence, I have welded up the end plate on the silencer and it seems to be holding up well, that plan didn't look as if it was going to happen in a hurry.
Once the bits were to hand, like an itch that has to be scratched, I simply had to get on with the job. So, having nothing else of importance to do this afternoon, I took the manifold off, filed the mating surfaces clean and flat, checked all the studs, helicoiled two of the threads into the block that appeared weak and put the car back together. I then found that one of the other studs refused to tighten, so off came the manifold again. The offending stud hole was helicoiled and the manifold replaced for the second time!
Took it on a test run and , as expected, the 'whicker' has gone. It still backfires on the overrun however, but not with the enthusiasm that it did. I obviously still have an air leak on the exhaust somewhere but I suspect that I shall have to live with that until one of the cherished suppliers can obtain further supplies.
Of course, now that I have disturbed the radiator drain tap, it has developed a slight, but persistent drip. Ah well, something else to add to the list.......
Ah yes! I also checked and topped up the rear axle. It seems that the only part of the car that does not try to divest itself of its vital fluids is the gearbox. When I first had the car, I drained it of the 'glue' that was in it, washed it out with kerosene and refilled with about 2/3rds of a pint of 20/50 which brought the level to within 1/2 in of the filler hole. And there it has stayed. I did think it was leaking from the gearchange turret, but this has turned out to be coming from the block to crankcase joint. Hmm. Something else to add to the list..........
I have been troubled ('plagued' is too strong a word) by niggling manifold problems ever since I bought FG in October last year. The first thing that I noticed was that one of the manifold studs at the rear had broken off, so , when I had the engine out to reline the clutch, I removed the manifold and drilled out the broken piece, re-threaded it and fitted a complete set of new studs. I noticed then that one or two of the block threads were a bit weak, but the new studs went in OK and appeared snug.
Then, one morning whilst I was on my way to Llangollen, one of the manifold studs came out and decanted the coolant all over the A5. Fortunately, the stud was lying on the side tray between the engine and the flitch plate, so it was jammed into its hole having wrapped the end with a piece of paper. Water was begged from a nearby house and I went on my way. A more permanent repair was effected when I got home using some 'magic' plumbers sealant that sets under water but I knew that I would have to deal with it eventually and so the problem was put on the (ever growing) list of things to be attended to when the car comes off the road this winter.
However, more recently, I have noticed a 'whicker' from the manifold on cold starts that goes away as the engine warms up, together with a tendency for the car to backfire on the overrun. Suspecting the manifold gasket, I ordered a new one and the aforementioned Helicoil kit to deal with any weak stud threads.
The original plan was to order an new exhaust system and do the manifold and exhaust at the same time, but given the difficulties already reported on this forum concerning exhaust system supplies, and, given that, in consequence, I have welded up the end plate on the silencer and it seems to be holding up well, that plan didn't look as if it was going to happen in a hurry.
Once the bits were to hand, like an itch that has to be scratched, I simply had to get on with the job. So, having nothing else of importance to do this afternoon, I took the manifold off, filed the mating surfaces clean and flat, checked all the studs, helicoiled two of the threads into the block that appeared weak and put the car back together. I then found that one of the other studs refused to tighten, so off came the manifold again. The offending stud hole was helicoiled and the manifold replaced for the second time!
Took it on a test run and , as expected, the 'whicker' has gone. It still backfires on the overrun however, but not with the enthusiasm that it did. I obviously still have an air leak on the exhaust somewhere but I suspect that I shall have to live with that until one of the cherished suppliers can obtain further supplies.
Of course, now that I have disturbed the radiator drain tap, it has developed a slight, but persistent drip. Ah well, something else to add to the list.......
Ah yes! I also checked and topped up the rear axle. It seems that the only part of the car that does not try to divest itself of its vital fluids is the gearbox. When I first had the car, I drained it of the 'glue' that was in it, washed it out with kerosene and refilled with about 2/3rds of a pint of 20/50 which brought the level to within 1/2 in of the filler hole. And there it has stayed. I did think it was leaking from the gearchange turret, but this has turned out to be coming from the block to crankcase joint. Hmm. Something else to add to the list..........