| Author | Message | ||
     felipe heuser Experienced User Username: felipe Post Number: 32 Registered: 7-2017 |
Hello all... Need some guidance with my SCIII sudden loud engine noise… After 25 years of ownership have I ever heard any engine noise until my recent drive home with only 6kl. before reaching my garage, a sudden relatively loud tapping appeared the remainder of the way. Checked oil when cold which was about half to maximum which I understand is sufficient for these engines. The temperature gauge throughout the drive was particularly low from the norm especially in summertime, and on the last stretch the oil pressure gauge was a bit erratic going from high to low repeatedly. Also noticed on the way before the tapping started the red generator light was permanently on. The following morning checked oil level again and added some of the same Castrol 20/50 from last years change. Starting engine cold but difficult to make out noise as it takes a few minutes at high revs with automatic choke on. At idle same tapping again and seems to be coming from both rocker covers which could be the hydraulic tappets. (but seem loader then the normal cold start tappet on my SS which goes away when hot) Can this occur without any warning with several tappets all at once? I had to drive the car out of the garage to make way to move another car, and I recall only for a few seconds tapping stopped while idling, however returning immediately. Could the oil pump be faulty and oil not circulating efficiently ? | ||
| Trevor Pickering Experienced User Username: commander1 Post Number: 38 Registered: 6-2012 |
Felipe This sounds like it may be the bronze drive gear for the oil pump wich is inside the timing case on the front of the engine. When they are well worn the teeth become like razors and it may be jumping what is left of the teeth and causing the erratic pressure readings. Do NOT run the engine again until you have investigated further. It sounds like the tappets are starved of oil! This gear can be changed with the engine in situe but you may have to remove the grill and rad to get access. Good luck Trevor Pickering 1964 SC111 SEV495 | ||
| felipe heuser Experienced User Username: felipe Post Number: 33 Registered: 7-2017 |
Trevor...that's interesting but have researched to find the pump malfunctioning is a rarity, however after much diagnose we've confirmed it’s the rear RH tappet making all that racket. (huge relief !) As mentioned never ever heard a tappet noise in this engine. During idling several minutes it actually stopped ticking but then returned and at the end of the day it stopped all together. However will do the complete oil change with some diesel to flush and fresh oil, including removing the sump this time to check for any sludge...and if that doesn’t sort it what would you suggest…tappet out and a good clean ? | ||
| Jim Walters Prolific User Username: jim_walters Post Number: 177 Registered: 1-2014 |
Before you drain the old oil out add a litre of Automatic Transmission Fluid (ATF) and run the engine for an hour. ATF has good detergent properties and will often clean sludge out of the hydraulic tappets. SRH8505 SRC18015 SRE22493 NAC-05370 www.bristolmotors.com | ||
| Mark Aldridge Grand Master Username: mark_aldridge Post Number: 547 Registered: 10-2008 |
Jim, it was suggested to me to leave 250ml of atf in the oil permanently, if the car is not used regularly. Has this any merit ? Mark | ||
| Christian S. Hansen Grand Master Username: enquiring_mind Post Number: 812 Registered: 4-2015 |
Felipe...but what about the fluctuating oil pressure? Clarify. Did it drop suddenly to zero, (or how low?) and then suddenly recover, or gradually? Did that symptom persist? If so, the tappet may be the result rather than the cause of the trouble. No oil pressure can lead to tappet noise, but how can tappet noise cause low oil pressure? Follow me? Also, the alternator light is curious and seemingly unrelated to either oil pressure or tappets. Hmmm.... . | ||
| Trevor Pickering Experienced User Username: commander1 Post Number: 39 Registered: 6-2012 |
Felipe The noisy tappet is probably caused by the low oil pressure problem if this is the case and not the cause of it. ATF may help the tappet but not the cause of the problem. The oil pump drive gear wear is more common than you may think. How many miles hase your engine done? The generator light and the oil pressure gauge erractic reading may be an electrical problem and the tappet noise a coincidence. Interesting!!!! Trevor | ||
| felipe heuser Experienced User Username: felipe Post Number: 34 Registered: 7-2017 |
Thanks for the input…the few miles I did before reaching my garage was not long enough to keep close tabs on the oil gauge but recall pointer going from top to bottom gradually and back again…speed (low) and couple of traffic lights could have been the cause as well… The generator light turned out to be a lose wire…sorted…also tested the oil gauge and functions correctly… Will try to measure oil pressure after changing the oil… Last winter rocker covers and tappet chest came off to change gaskets. Mileage is about 170K… | ||
| Geoff Wootton Grand Master Username: dounraey Post Number: 1983 Registered: 5-2012 |
Felipe I would invest in an oil pressure test kit. They are cheap here in the US. Are there low cost tools in Spain? https://www.harborfreight.com/engine-oil-pressure-test-kit-62621.html | ||
| Trevor Pickering Experienced User Username: commander1 Post Number: 40 Registered: 6-2012 |
From what you have said I would still suspect the oil pump drive gear. Try and check the oil pressure by removing the sender on the engine and connect a pressure gauge here. That will tell you if the oil pump is the problem. If this is the case shut the engine down straight away. Good luck Trevor Pickering | ||
| felipe heuser Experienced User Username: felipe Post Number: 35 Registered: 7-2017 |
Since having read last posts, started the engine and took a short drive round to monitor the tappet ticking which was now coming and (mostly) going, rather than continuously such as the first time. Have ordered oil and filter and will see where I can purchase / borrow a gauge. To view the drive gear I believe the radiator and front covers are to be removed to access oil pump ? Last year for the first time, after researching several opinions decided to change form 10W40 semi synthetic to Castrol Classic 20/50 mineral…any chance the cause for the sudden tappet ticking? | ||
| felipe heuser Experienced User Username: felipe Post Number: 36 Registered: 7-2017 |
Oh and BTW, the oil gauge pointer was correctly in the middle during my short drive... | ||
| Trevor Pickering Experienced User Username: commander1 Post Number: 41 Registered: 6-2012 |
It would be a very good idea to check the oil pressure soon. Yes you do have to remove grill and radiator etc. to give access to the timing cover. There is obviously a viscosity difference in the oil but I do not think this would cause a problem but an Oil "Guru" may know better. I run my Cloud on Castrol Classic 20/50 as well. If the oil pressure proves to be OK but the tappets are still noisy after a good run it may be wise to remove them all and take them all appart for a real good clean. best regards Trevor | ||
| felipe heuser Experienced User Username: felipe Post Number: 39 Registered: 7-2017 |
Any truth in the following post? On 'clacking' in the hydraulic vale gear lifters/cam followers, I drain all the old oil off hot, fit a new oil filter, then use a good brand DIESEL grade 10-40 engine oil for 2-3000 miles. Diesel grade oil is simply regular oil with added slow acting detergents which do an effective job of cleansing away much of the muck and sludge that accumulates in all engines as the miles build up. Some engines are much more prone to muck build up than others. When I drain the DIESEL oil off my petrol cars, the filth that comes out is remarkable. I then fill up with good brand 10-40 semi synthetic as recommended by the manufacturer. That clacking goes away EVERY time ! Not only that, checking the oil on the dipstick several hundred miles later after the DIESEL oil treatment show nice clean clear oil on the dip stick. Simply changing the oil in the normal way would see black oil on the dip stick within a few miles. Contaminated by the muck that always remains in the engines. | ||
| Trevor Pickering Experienced User Username: commander1 Post Number: 46 Registered: 6-2012 |
It may help but if it is a defective tappet no amount of treatment will cure it. A detergent oil may shift some of the muck and help matters. Did you test your oil pressure? regards Trevor | ||
| felipe heuser Experienced User Username: felipe Post Number: 40 Registered: 7-2017 |
I'm patiently waiting for my mechanic this week to test the oil pressure with his gauge and filter/oil change... | ||
| Trevor Pickering Experienced User Username: commander1 Post Number: 48 Registered: 6-2012 |
Thats good Felipe Let us know what the results of the oil pressure test are. The pressure test can be carried out by removing the sender that is situated on the top of the oil filter housing. Good access can be gained by removing the spark plug access panel under the left front wing. | ||
| felipe heuser Experienced User Username: felipe Post Number: 41 Registered: 7-2017 |
Still no luck in finding a mechanic with a pressure gauge...some disadvantages living on an island ! We checked the gauge on the dash which is working correctly… Have drained some oil and poured in half a litre of ATF as many have suggested and topped up with fresh oil to almost the maximum… Idling to warm up and mostly ticking, however stopping irregularly…after a short drive continued ticking but on return stopped and idling for about 20+ minutes with no ticking, pressure and temperature normal… Following morning fired up to a lot of ticking and later in the afternoon drove out for approx. 100 kilometres with no ticking the entire drive… with several long stops along the way… pressure gauge pointer mostly in the middle when cruising 60/70 KPH unless accelerating when pointer went to high and idling to low…temperature normal… Quite pleased about this outcome and next step is a full oil & filter change with hopefully quite results ! | ||
| felipe heuser Experienced User Username: felipe Post Number: 43 Registered: 7-2017 |
Are GM tappets, at a fraction of the price, compatible to the expensive after market R-R counterparts ? | ||
| David Gore Moderator Username: david_gore Post Number: 2966 Registered: 4-2003 |
Felipe, To the best of my knowledge, I am not aware of any GM hydraulic lifters being compatible with the 6.25L/6.75L R-R V8 engine. About 20 years ago, there were mentions of a compatible US Chrysler V8 hydraulic lifter however no-one ever mentioned a part number. It would be very helpful if anyone knows of a compatible lifter and who can provide the details for future reference. | ||
| felipe heuser Experienced User Username: felipe Post Number: 44 Registered: 7-2017 |
I assumed the original V-8 engine owed some of its design to GM technology, hence the equivalent tappets... | ||
| David Gore Moderator Username: david_gore Post Number: 2967 Registered: 4-2003 |
Felipe, Rolls-Royce had a long tradition of making "V" block engines before the Cloud/Shadow V8 engine was introduced post-WW2. Just look at the R-R Merlin V12 from WW2 as one example however the first R-R V8 was made in 1905 and there are no surviving examples: https://en.wikipedia.org/wiki/Rolls-Royce_V8_engine R-R would certainly have looked at V8 engines from other manufacturers over the years however my opinion is the post-WW2 V8 benefited greatly from the knowledge and experience R-R gained from the WW2 Merlin V12 project rather than by copying from other car manufacturers. It is also conceivable the US car manufacturers benefited from R-R licencing Packard to manufacture the Merlin V12 in the USA during WW2 for installation in US military aircraft. | ||
| David Balfour Prolific User Username: sidchrome Post Number: 102 Registered: 2-2009 |
Hi David, May I add that the Americans were already automotive V8 engine experts by the start of WWII and Packard Merlin production. There is an excellent video on youtube about the mass production of the Ford V8 engine, https://www.youtube.com/watch?v=3RB3z1er9Sw which was the first mass produced V8 engine in the world. Up until then only high end cars had V8s like Cadillac-LaSalle, Lincoln etc. I think Packard particularly ran straight 8's and the iconic double six. Later of course some Cadillacs had the V16 and Lincoln had a V12. the Lincoln Zephyr had a flathead V12 which was derived from the Ford L-head V8. There is also an interesting debunking article as some people think the Rolls-Royce V8 is a copy of an American V8 of some persuasion, which is of course patently incorrect. It is on our very own RROCA website: https://rroc.org.au/wiki/index.php?title=Rolls-Royce_FAQ:_Myths_and_Legends Which under the myth heading of "The Rolls-Royce engine is a copy of an American Chevrolet V8"explains why this myth is exactly that. | ||
| Trevor Pickering Experienced User Username: commander1 Post Number: 49 Registered: 6-2012 |
Felipe A word of caution regarding tappets. The tappets are individually graded to their tappet blocks and are marked as such. Be very careful if you decide to fit new after market tappets as they will have to be lapped to get a precise and accurate fit into their individual blocks. Why not just remove all the existing tappets and take them appart and clean them? If you decide to do this they must go back in the same place they were removed from. They come appart easily if you first depressurize them by using a cocktail stick or similar to insert in the top of the tappet and push down on the disc at the bottom. Clean them in Meths or similar and ensure that they are kept spotless. Recharge them with engine oil prior to installation. Hope this helps | ||
| felipe heuser Experienced User Username: felipe Post Number: 45 Registered: 7-2017 |
Many thanks and that’s then decided...no experiments with other than OEM parts or cleaning as suggested… However as I'm not an engineer will have to rely on advice and my mechanic here… Seems though things aren’t going terribly well…after hoping to change oil & filter to establish results of tappet noise, the new starter motor decided to pack up…removed and found it has the front bearing housing damaged and broken off…hence no testing possible at present ! On the other post this week where I added my positive experience with a new alternative starter motor, has only confirmed sod’s law… | ||
| Trevor Pickering Experienced User Username: commander1 Post Number: 50 Registered: 6-2012 |
Use the old ones if they are ok when you remove and inspect them. The surface that contacts the cam can be lightly lapped to get rid of any pitting etc You may recall some time ago I suggested that the "high torque" lightweight starter motors can be a problem. The gear on the bendix does not contact the full width of the ring gear on the car and they require careful adjustment to ensure the teeth mesh at the correct depth. Sounds like this may be the cause of your problem! Too much side load Once again revert to the original starter | ||
| felipe heuser Experienced User Username: felipe Post Number: 46 Registered: 7-2017 |
Tappets issue will have to be shelved for the time being until engine running again... How can one adjust starter accurately as there’s only one position...unlike original which has an adjustable screw on the outer casing? To speed things up, received a new motor as they’re on warranty...furthermore was told this is the first faulty example... My old motor was extremely slow and at times only a grunt, where then repositioned ring gear with a screwdriver to work… When removed the front case found broken off (believe cast iron) and the very front bendix worn off... | ||
| Trevor Pickering Frequent User Username: commander1 Post Number: 52 Registered: 6-2012 |
Has the ring gear been changed ? Sounds like it is damaged and this may be the cause of the problem. If the teeth are worn with some broken you will have constant problems what ever starter motor you use. If this is the case you will have to remove the gearbox to replace the ring gear.  | ||
| felipe heuser Experienced User Username: felipe Post Number: 47 Registered: 7-2017 |
Ring gear is original with one tooth missing since ownership but otherwise in good condition... | ||
| Trevor Pickering Frequent User Username: commander1 Post Number: 53 Registered: 6-2012 |
Even one broken tooth can cause a problem. If you happen to try and start when the broken tooth is at or next to your starter bendix it can cause a momentary overspeed of the starter and when it does engage it will put enormous strain on the starter and the teeth next to the break. Do you want to fit a new starter motor(original type recommended) and risk further problems? This may be the reason your current starter has broken. It may be better to "bite the bullet" and replace the ring now | ||
| David Balfour Prolific User Username: sidchrome Post Number: 112 Registered: 2-2009 |
My SCII now has the tapping bug too. I'm thinking about pulling them out and giving them a clean while I'm off at Christmas, will I need to obtain a new tappet cover gasket and rocker cover gaskets before I embark on this probably long overdue activity? If so, where is the cheapest source of these within AU, and the cheapest source to buy in. I have used intro car and Flying Spares before, on several occasions as well as others. Suggestions! |
