dropped valve

Author
Discussion

aitkindrum

Original Poster:

41 posts

216 months

Tuesday 3rd September 2002
quotequote all
just bought '99 griff with 12000 miles from dealer with full service. drove 35 miles and suddenly engine vibrated and would not idle. as sunday only salesman working told me if poss to drive home which i did further 10miles. car collected and dealer eventually states 'dropped valve' possibly bent not broken. don't know yet whether inlet or exhaust. am bit pissed off. couldn't afford car in first place.
dealer obviosly fixing engine however when i go back to bahter wonder if anybody any experience of similar in relatively young griff? once mechanics fixed is there any likelyhood of associated damage i.e. crank bearings, cam, catalytic's etc? anything else i should be aware of? ta

GreenV8S

28,302 posts

241 months

Tuesday 3rd September 2002
quotequote all
quote:
just bought '99 griff with 12000 miles from dealer with full service. drove 35 miles and suddenly engine vibrated and would not idle. as sunday only salesman working told me if poss to drive home which i did further 10miles. car collected and dealer eventually states 'dropped valve' possibly bent not broken. don't know yet whether inlet or exhaust. am bit pissed off. couldn't afford car in first place.
dealer obviosly fixing engine however when i go back to bahter wonder if anybody any experience of similar in relatively young griff? once mechanics fixed is there any likelyhood of associated damage i.e. crank bearings, cam, catalytic's etc? anything else i should be aware of? ta


The rover engine is pretty bullet proof as long as you don't over-rev it. A dropped valve is a very unusual problem. But if the piston has smacked a valve, it could potentially have done a lot of damage. This may be too late to do you any good (then again, maybe just in time?) but don't underestimate the cost of running a TVR, and if you try to cut corners on maintenance it can go downhill quickly.

danny hoffman

1,617 posts

219 months

Wednesday 4th September 2002
quotequote all
I have never heard of a Rover V8 dropping a valve when used on the road. As I understand it the hydraulic tappets prevent over reving unless you change down to too lower gear. Strange.

Please let us know the outcome

Danny

RichB

43,577 posts

241 months

Wednesday 4th September 2002
quotequote all
What exactly is meant by a "dropped" valve? I had one stick open on my engine when new, due to a blocked oilway but it was fixed by TVR Power. Rich...

danny hoffman

1,617 posts

219 months

Wednesday 4th September 2002
quotequote all
I understand a dropped valve to be one that has hit a piston.

JSG

2,238 posts

240 months

Thursday 5th September 2002
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quote:

The rover engine is pretty bullet proof as long as you don't over-rev it. A dropped valve is a very unusual problem.


Don't the V8's have a rev limiter to prevent this?

Cheers,
JSG.

whatever

2,174 posts

227 months

Thursday 5th September 2002
quotequote all
quote:

quote:

The rover engine is pretty bullet proof as long as you don't over-rev it. A dropped valve is a very unusual problem.


Don't the V8's have a rev limiter to prevent this?

Cheers,
JSG.



but rev-limiters work by regulating fuel, ultimately, and won't do you any good if you over-rev by driving the engine from the rear-wheels, by changing into 2nd at 100mph, for example, as a previous poster mentioned.

johno

8,129 posts

239 months

Tuesday 10th September 2002
quotequote all
A totally dropped valve would mean that the valve collets or whatever method of preventing it from doing it having come out and the valve 'drops' into the cylinder through the head.

In reality it is extremely difficult for the valve to do this due to the movement of the piston. This though is where the damage starts to occur as the piston slams into the valve and bends it, breaks and lunch cylinder.

Not always the outcome though and hopefully in this case it isn't ...