Rough-runner - need some ideas..!

[lil_red_roadster]

Rough running Rover T Series...need some fresh ideas where the issue might lie because I've run out..!

It all started with a metallic clunk from the engine bay when I was giving it the beans & then it started running rough...felt like a minor misfire & generally chugs a bit. Driveable but not confidence-inspiring.

Symptoms include what sounds like tappet noise which persists (i.e. doesn't go away after a few minutes); fluctuating oil pressure which spikes up to 100psi when throttle even lightly depressed but registers normal at idle.
It's not overheating and there is no smoke/leaks. A compression test looks OK (even across all 4 cylinders). Plugs all OK & all cylinders are firing.

Sensors all appear to be OK and all registering sensible values...it's an Emerald ECU so I can plug it in to see what's happening...but no clues there.

Any ideas welcome

[chris_cussen]

Re: Rough-runner - need some ideas..!

Only a wild guess, but ojl pressure relief valve?

[Alan c]

Re: Rough-runner - need some ideas..!

Try taking the leads off one at a time to see which one makes no difference to identify problem cylinder and pressure test cylinders. As its sounds like you have damaged a valve or a valve spring.

[cameronfurnival]

Re: Rough-runner - need some ideas..!

did you do a wet compression (with a squirt of oil in the bore) as well as a dry one?

[lil_red_roadster]

Re: Rough-runner - need some ideas..!

Thanks chaps.
Oil pressure relief valve appears OK...piston free & spring unbroken.
Compression test was dry only - looks like I'll have to do a wet one as well.
There's no misfire as such, just rough running & the constant tappet noise...which could be a stuck lifter or something more serious. I'd have expected a sticky tappet to come on gradually, rather than suddenly.

Hey ho, whatever it is is going to need a degree of dismantling to find...I do love getting the cams timed in correctly - not..!

[Gareth]

Re: Rough-runner - need some ideas..!

Just a thought...camshaft snapped???
Good luck,
Gareth.

[cameronfurnival]

Re: Rough-runner - need some ideas..!

Have you thought about installing a nice B series engine?

Whip of the cam cover and have a butchers. Im guessing somethings broken and fallen off.

[lil_red_roadster]

Re: Rough-runner - need some ideas..!

Crossed my mind...but someone bought all my "useful" bits :-)
Have had the covers off already - nothing obvious tinkling about in there.

[neiltechspec]

Re: Rough-runner - need some ideas..!

Not familiar with that engine, but

Sounds like it could be a busted cam follower or,

Does it have hydraulic tappets - one could have failed giving too much clearance causing the noise & not enough lift which would affect performance.

Neil

[cameronfurnival]

Re: Rough-runner - need some ideas..!

Timing belt jumped a tooth? Maybe a tensioner? they can rattle like buggery.

[lil_red_roadster]

Re: Rough-runner - need some ideas..!

Belt & tensioner have < 3k on them...but I did wonder about skipping a tooth.
It's a strip-down whatever...nose cone off, radiator out so I can get at the belt, then maybe get the head off.
Which means new stretch bolts, cam carrier sealant, gaskets, oil, filter, anti-freeze...there's > £100 before I've even started...and there's a T&T, complete Rover 220 on eBay for £200..!
Makes you think.

[cameronfurnival]

Re: Rough-runner - need some ideas..!

hmm, my thoughts about cam tensioner wouldnt account for the high oil pressure. I would maybe hazard a guess that the oil pump itself is broke. Isn't that pump one with a gear in it - sits on the end of the crank like the K series? Mind you - how about this...

191186680937

[lil_red_roadster]

Re: Rough-runner - need some ideas..!

Timing belt jumped a tooth? Maybe a tensioner? they can rattle like buggery.

Finally spent some time removing bits so I can see what's what...and Cameron you were right.

With the cams set in the correct position for timing, the crank pulley mark is no longer where it should be (90 degrees BTDC). It's lagging by quite a lot...more like 140 BTDC...so clearly the "sticky tappet" noise is more of a "valve/piston interface" noise Still there are no mechanical noises on cranking so I might have got away without serious damage...fingers crossed.

Running heavily retarded would also explain the increased heat in the engine bay, which probably served to cook a few things...the oil pressure relief valve seemed to be sticking intermittently and as a result the ally pump housing has cracked (luckily I have a spare oil pump and Rimmers have them as a clearance bargain at the moment..!). New belt is probably a good idea as well.

Onwards & sideways...

[cameronfurnival]

Re: Rough-runner - need some ideas..!

bent valves would show up on the compression test - so yes. fingers crossed glad you decided to fix it - another pitstop article in the offing?