rattley engine

[Nic Bowman]

Hi, just finished my TR4a rebuild, it needed mainly finishing, and was rust freee, looks fantastic. The engine has not been run for a few years, but oil is clean, and it runs okay when sat in the garage. First on the road experience, the engine rattles loudly at mid throttle, not at low power and not at full power. Any ideas? Timing chain?

 

Thanks

 

Nic

[Don Elliott]

My first thought was that it's the timing chain tensioner. My experience is that they last about 35,000 miles or maybe a bit more. The chain is very strong and robust so I don't think it's the chain. If you let up on the throttle - just as the engine is neither accelerating nor decelerating, the chain will "clatter" back and forth in this neutral force situation because of the weak or broken timing chain tensioner.

 

Don't worry about it for now. Plan all the things you want to do (or need to do) with the front valance off. Then do all these changes at the same time that you change your timing chain tensioner.

 

TRactor engines clatter all the time.

[TR 2100]

I seem to recall that TR engines often have a some kind of natural resonance in

the mid-rev range. This can be made worse by vibration of the exhaust just about

anywhere where it runs near the chassis, but often most critical where it runs

through the centre cruciform.

 

This sounds a bit like "TRs don't leak oil, they just mark their territory" but

that's the way it is.

 

AlanR

[Alec Pringle]

I once had a sidescren car that rattled like blazes around the 3000rpm mark, not a happy sound.

 

Answer turned out to be resonance resulting from a solid exhaust mount, on a non-standard exhaust system . . . replaced with flexible mount, after some hammering and levering of the pipe to clear the chassis (as in sledge hammer and scaffold pole). Problem solved.

 

Worth checking, there's just a chance this may be your problem . . .

 

Cheers,

 

Alec

[RogerH]

Hi Nic,

on my original 4A in the 70's I got picked up by the fuzz (very painful) at apprx midnight and the copper asked me to shut the engine off due to the horrendous racket.

The following day upon striping bits of the engine I found the woodruff key slot in the crank at the front pulley had opened up and the pulley was whacking back and forth.

This was at apprx 1000RPM.

 

Roger

[Nic Bowman]

Thanks for the replies. It may be partially down to pinking, old petrol post rebuild (3 years!). It is having some cursory checks tomorrow whilst mot'ed. Will update.

 

Thank again

 

 

Nic

[Nic Bowman]

Thanks for the replies. It may be partially down to pinking, old petrol post rebuild (3 years!). It is having some cursory checks tomorrow whilst mot'ed. Will update.

 

Thank again

 

 

Nic

 

Pulled the sump off, big ends knackered. new shells and thick oil for summer, engine out in winter. Nic

[Colin Fairhurst]

Hi Nick, Just out of interest, are the crnkshaft big ends scored as well?

This is the situation with our Tr2 after 1000 miles or so. I completed a partially rebuilt engine which had had a reground crankshaft fitted (+20 shells) and now experience a rattle on start-up every time. Although there is no evidence of this,my only explanation is that the crankshaft oilways were not flushed out properly.

I have decided to look for a TR4a engine and carbs etc and do a straight swop.

Regards, Colin.