ismymiddlename Posted March 23, 2009 Report Share Posted March 23, 2009 My Tr4 has developed a knock/rattle.The car is running well Oil pressure is good Tappets checked and okay. The rattle is present at low revs but appears to disapear under load It is difficult to pin point the source it does not appear to come from the timing chain area Any ideas? Quote Link to post Share on other sites
MadMarx Posted March 23, 2009 Report Share Posted March 23, 2009 Maybe this: - piston slap - wrist pin bore wear - piston is hitting the head maybe cause by wrist pin - worn cam lobe - crank bearing rumble Cheers Chris Quote Link to post Share on other sites
wvukidsdoc Posted March 24, 2009 Report Share Posted March 24, 2009 Add to the list loose key or other looseness in the oil pump/dizzy drive shaft... Actually a bit less intimidating that the other causes mentioned. John Quote Link to post Share on other sites
anytr Posted March 24, 2009 Report Share Posted March 24, 2009 My Tr4 has developed a knock/rattle.The car is running well Oil pressure is good Tappets checked and okay.The rattle is present at low revs but appears to disapear under load It is difficult to pin point the source it does not appear to come from the timing chain area Any ideas? Have you checked the fan belt ? my fan belt had a split and it sent out a terrible sound from the engine bay ( but only on tickover ). Quote Link to post Share on other sites
jerrytr5 Posted March 24, 2009 Report Share Posted March 24, 2009 Use a long screwdriver as a stethoscope (watch out for rotating bits) to try and pinpoint the noise. Does it stop when you put your foot on the clutch? If it does, it could be the gearbox or flywheel area. Quote Link to post Share on other sites
BrianC Posted March 24, 2009 Report Share Posted March 24, 2009 (edited) Have you checked the fan belt ? my fan belt had a split and it sent out a terrible sound from the engine bay ( but only on tickover ). I've had this several times on TRs with the original smooth/un-cogged/un-notched fanbelts. It's often the first warning of a belt on its last legs and sounds much worse than it is (although if it does let go then things can get much worse/expensive). Edited March 24, 2009 by BrianC Quote Link to post Share on other sites
Tom Fremont Posted March 24, 2009 Report Share Posted March 24, 2009 My TR4 rattled like a diesel when hot, at idle. Worn rockers/ rocker shaft were the culprit, and a $10 junkyard replacement rocker shaft assembly made it go away ( circa 1975 ). You can check these by twisting the rocker arms around an axis perpendicular to the shaft; if good they wont rotate at all; if bad you'll get some play here. I can recommend an excellent rebuilder of these in the 'states. Quote Link to post Share on other sites
Don Elliott Posted March 25, 2009 Report Share Posted March 25, 2009 We were on holiday in Cape Cod, 400 miles from home about 5 years ago when the engine in my 1958 TR3A developed a horrible rattle at low RPM. At least, I thought it was the engine. Always the worst. At load or when driving, it was gone, but if I hit a few bumps in the road it was there. I pulled over into a safe car-park and crawled under the front. It was the rods that are supposed to secure the alignment piece just behind the grille to add support for the handcrank (TR3A) and those rods were loose and rattling. Five minutes later they were tight and my worries had gone. Sometimes I just get lucky. You can never tell where the gremlins will try to get you next time. Don Elliott, Original Owner, 1958 TR3A Quote Link to post Share on other sites
67_gt6 Posted March 26, 2009 Report Share Posted March 26, 2009 We were on holiday in Cape Cod, 400 miles from home about 5 years ago when the engine in my 1958 TR3A developed a horrible rattle at low RPM. At least, I thought it was the engine. Always the worst. At load or when driving, it was gone, but if I hit a few bumps in the road it was there. I pulled over into a safe car-park and crawled under the front. It was the rods that are supposed to secure the alignment piece just behind the grille to add support for the handcrank (TR3A) and those rods were loose and rattling. Five minutes later they were tight and my worries had gone. Sometimes I just get lucky. You can never tell where the gremlins will try to get you next time. Don Elliott, Original Owner, 1958 TR3A Similar experience, I had a noise which I thought maybe indicated broken timing chain tensioner, turned out to be the nuts/bolts holding the aluminium number plate onto the fron bumper were not properly fastened => horrible expensive sounding clatter at idle. andy Quote Link to post Share on other sites
pfenlon Posted March 26, 2009 Report Share Posted March 26, 2009 We were on holiday in Cape Cod, 400 miles from home about 5 years ago when the engine in my 1958 TR3A developed a horrible rattle at low RPM. At least, I thought it was the engine. Always the worst. At load or when driving, it was gone, but if I hit a few bumps in the road it was there. I pulled over into a safe car-park and crawled under the front. It was the rods that are supposed to secure the alignment piece just behind the grille to add support for the handcrank (TR3A) and those rods were loose and rattling. Five minutes later they were tight and my worries had gone. Sometimes I just get lucky. You can never tell where the gremlins will try to get you next time. Don Elliott, Original Owner, 1958 TR3A Don be honest now did your radiator still have the "hole" in it and where do you store your starting handle. Pete Quote Link to post Share on other sites
Bob Brennan Posted March 26, 2009 Report Share Posted March 26, 2009 Don be honest now did your radiator still have the "hole" in it and where do you store your starting handle. Pete As I recall Pete, Don did retain the crank hole when he last recored his radiator. I didn't, on TS 24528, preferring to keep those four extra tubes flowing. Not sure where he keeps that crank handle! According to my original owner's log, there were competitions to see who could start their TR, via crank, the fastest. Perhaps Don remembers. Quote Link to post Share on other sites
Don Elliott Posted March 26, 2009 Report Share Posted March 26, 2009 I had my radiator re-cored in 1990 during my restoration and it has the hole for the handcrank. I carry the crank in the boot all the time. And it works. When I show my 1958 TR3A at an open or public car show where the cars are only "on display", I put the hand crank through the grille and have a competition. First I would ask people to identify what that is sticking out the front of my TR. Many people younger than 45 or 55 have never seen a handcrank. Next I ask three young lads to try to turn the crank with the bonnet up and the key turned on. I have one hand on the throttle linkage. The age seems to be about 13 or 14 when a boy can turn the crank and get the engine started. The ones who can do it have a smile from ear to ear. Everyone watching is amazed when it starts. It starts so quietly, they can't believe it. It's a nice feeling when I have made their day ! Quote Link to post Share on other sites
Horse Posted March 31, 2009 Report Share Posted March 31, 2009 I have a 4A which delevoped a rattle from the front end which sounded for all the world like the clearance on one tappet being too large. Worse when cold and particularly noticeable on the overrun. The (large) consenus view was that it was either piston slap or little end wear, most dianosing the former. However, as it had come on quite quickly the odds were no 1 cylinder little end and so it proved. The good news for the correspondant is that I used it in this condition for the whole of last season without problems so it will probably last without problem until the winter. Quote Link to post Share on other sites
LETSRACE Posted April 2, 2009 Report Share Posted April 2, 2009 I suffered an annoying rattle on my 1500 Spitfire and it ended up being the chainwheel on the cam face being loose. Torque those bolts and lock'em down with the metal tabs......Dennis Quote Link to post Share on other sites
Smokey Posted April 9, 2009 Report Share Posted April 9, 2009 I had a rattle at low revs that my mechanic claimed was piston slap. The engine had supposedly been rebuilt by the previous owner, so I though I'd check the oil pump shaft and key as outlined in Roger William's TR4 restoration book. I just replaced the shaft and the key, and the noise is now gone. The old key was noticeably loose, and the new key was so tight I had to use a vise to insert it. So no piston slap, and a relatively easy fix. Quote Link to post Share on other sites
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