Rattling rebuilt Rover V8
Discussion
Interested in views from those with Rover V8 engine building experience.
A few thousand miles ago I had my Chimaera's 3.9 RV8 professionally rebuilt by a specialist. The engine is still under warranty and I’d prefer to keep the builder anonymous as this isn’t intended as a criticism or a naming and shaming exercise.
The engine runs well, makes good power and has healthy oil pressure. However, it developed a noticeable rattle during rev decay and on the overrun at low road speeds days after collection. The builder has listened to it in person and stated that he believes it is likely piston / small-end related, although he is not currently concerned by it.
What has left me questioning things is that I originally took the engine in due to a lifter tick and general wear concerns. Once the decision to rebuild was made, I authorised a full rebuild without hesitation and budget genuinely wasn’t the driving factor. I was happy to spend what was required to end up with the best engine possible and numerous upgrades were discussed and carried out during the build. I did not expect the end result to include rattling on the overrun.
What was never discussed, however, was piston replacement. At the time I was fairly green when it came to Rover V8s and simply assumed that anything worth replacing would either be replaced or at least offered as an option. In hindsight, knowing what I know now, I would certainly have wanted that discussion.
So I’m interested in hearing from those who rebuild or have rebuilt these engines:
- Is piston replacement routinely offered on a 3.9 rebuild, or only if measurements dictate?
- Is it common practice to reuse original pistons without issue?
- Have you encountered small-end / gudgeon pin noise after a rebuild where the engine otherwise performed perfectly well?
- Given the circumstances above, are my concerns justified, or am I worrying unnecessarily about what is effectively a normal Rover V8 characteristic?
I’m not looking to start an argument with the builder, particularly as the engine remains under warranty. I’m simply trying to understand what would generally be considered normal practice and whether others have encountered something similar.
A few thousand miles ago I had my Chimaera's 3.9 RV8 professionally rebuilt by a specialist. The engine is still under warranty and I’d prefer to keep the builder anonymous as this isn’t intended as a criticism or a naming and shaming exercise.
The engine runs well, makes good power and has healthy oil pressure. However, it developed a noticeable rattle during rev decay and on the overrun at low road speeds days after collection. The builder has listened to it in person and stated that he believes it is likely piston / small-end related, although he is not currently concerned by it.
What has left me questioning things is that I originally took the engine in due to a lifter tick and general wear concerns. Once the decision to rebuild was made, I authorised a full rebuild without hesitation and budget genuinely wasn’t the driving factor. I was happy to spend what was required to end up with the best engine possible and numerous upgrades were discussed and carried out during the build. I did not expect the end result to include rattling on the overrun.
What was never discussed, however, was piston replacement. At the time I was fairly green when it came to Rover V8s and simply assumed that anything worth replacing would either be replaced or at least offered as an option. In hindsight, knowing what I know now, I would certainly have wanted that discussion.
So I’m interested in hearing from those who rebuild or have rebuilt these engines:
- Is piston replacement routinely offered on a 3.9 rebuild, or only if measurements dictate?
- Is it common practice to reuse original pistons without issue?
- Have you encountered small-end / gudgeon pin noise after a rebuild where the engine otherwise performed perfectly well?
- Given the circumstances above, are my concerns justified, or am I worrying unnecessarily about what is effectively a normal Rover V8 characteristic?
I’m not looking to start an argument with the builder, particularly as the engine remains under warranty. I’m simply trying to understand what would generally be considered normal practice and whether others have encountered something similar.
The original pistons are often re used if bores and piston condition are within tolerance. Bores are just re honed and new piston rings are fitted and gapped accordingly.
The general consensus is the original pistons are stronger and more reliable than after market replacements so if there is no evidence of damage on either the pistons or bores they are re used.
If your getting good compression figures and power is good this suggests that area is working well.
Ordinarily the issues regarding small end rattle are more associated with the 5.0 litre engine but that doesn’t mean it can’t or doesn’t exist on the more standard smaller engines.
I had my 4.6 rebuilt and I also worried about slight rattles here and there of which the engine builder didn’t seem concerned. I did over 25,000 miles on that engine and power was as good after those miles as it was when rebuilt.
We are talking about a very old engine design and to some extent you have to expect it will never sound like a very modern engine design.
I constantly listened to my engine over those years after rebuild and could never really track down where the odd rattle/ rattles came from and then one day used some quality injector cleaner lubricant and low and behold my engine was much quieter after. This sounds like a red heron but well worth chucking a bottle of cleaner into your fuel and see if it makes any difference.
If you look at the nature of the small end on these engines they are always likely to rattle a bit as soon as they re run in similar to two stroke engines and that’s always been seen as completely normal on those type of engines so my view is if the builder isn’t concerned then just use the car and if it’s under warrantee it will probably last another 20 years.
Your issue has been around for years and you’re not the only one wondering about it.
The general consensus is the original pistons are stronger and more reliable than after market replacements so if there is no evidence of damage on either the pistons or bores they are re used.
If your getting good compression figures and power is good this suggests that area is working well.
Ordinarily the issues regarding small end rattle are more associated with the 5.0 litre engine but that doesn’t mean it can’t or doesn’t exist on the more standard smaller engines.
I had my 4.6 rebuilt and I also worried about slight rattles here and there of which the engine builder didn’t seem concerned. I did over 25,000 miles on that engine and power was as good after those miles as it was when rebuilt.
We are talking about a very old engine design and to some extent you have to expect it will never sound like a very modern engine design.
I constantly listened to my engine over those years after rebuild and could never really track down where the odd rattle/ rattles came from and then one day used some quality injector cleaner lubricant and low and behold my engine was much quieter after. This sounds like a red heron but well worth chucking a bottle of cleaner into your fuel and see if it makes any difference.
If you look at the nature of the small end on these engines they are always likely to rattle a bit as soon as they re run in similar to two stroke engines and that’s always been seen as completely normal on those type of engines so my view is if the builder isn’t concerned then just use the car and if it’s under warrantee it will probably last another 20 years.
Your issue has been around for years and you’re not the only one wondering about it.
BritishTvr450 said:
The original pistons are often re used if bores and piston condition are within tolerance. Bores are just re honed and new piston rings are fitted and gapped accordingly.
The general consensus is the original pistons are stronger and more reliable than after market replacements so if there is no evidence of damage on either the pistons or bores they are re used.
If your getting good compression figures and power is good this suggests that area is working well.
Ordinarily the issues regarding small end rattle are more associated with the 5.0 litre engine but that doesn t mean it can t or doesn t exist on the more standard smaller engines.
I had my 4.6 rebuilt and I also worried about slight rattles here and there of which the engine builder didn t seem concerned. I did over 25,000 miles on that engine and power was as good after those miles as it was when rebuilt.
We are talking about a very old engine design and to some extent you have to expect it will never sound like a very modern engine design.
I constantly listened to my engine over those years after rebuild and could never really track down where the odd rattle/ rattles came from and then one day used some quality injector cleaner lubricant and low and behold my engine was much quieter after. This sounds like a red heron but well worth chucking a bottle of cleaner into your fuel and see if it makes any difference.
If you look at the nature of the small end on these engines they are always likely to rattle a bit as soon as they re run in similar to two stroke engines and that s always been seen as completely normal on those type of engines so my view is if the builder isn t concerned then just use the car and if it s under warrantee it will probably last another 20 years.
Your issue has been around for years and you re not the only one wondering about it.
Thanks, that’s useful.The general consensus is the original pistons are stronger and more reliable than after market replacements so if there is no evidence of damage on either the pistons or bores they are re used.
If your getting good compression figures and power is good this suggests that area is working well.
Ordinarily the issues regarding small end rattle are more associated with the 5.0 litre engine but that doesn t mean it can t or doesn t exist on the more standard smaller engines.
I had my 4.6 rebuilt and I also worried about slight rattles here and there of which the engine builder didn t seem concerned. I did over 25,000 miles on that engine and power was as good after those miles as it was when rebuilt.
We are talking about a very old engine design and to some extent you have to expect it will never sound like a very modern engine design.
I constantly listened to my engine over those years after rebuild and could never really track down where the odd rattle/ rattles came from and then one day used some quality injector cleaner lubricant and low and behold my engine was much quieter after. This sounds like a red heron but well worth chucking a bottle of cleaner into your fuel and see if it makes any difference.
If you look at the nature of the small end on these engines they are always likely to rattle a bit as soon as they re run in similar to two stroke engines and that s always been seen as completely normal on those type of engines so my view is if the builder isn t concerned then just use the car and if it s under warrantee it will probably last another 20 years.
Your issue has been around for years and you re not the only one wondering about it.
To be clear, I’m not particularly concerned that the engine is about to fail. It runs well, makes good power and otherwise behaves exactly as I’d expect.
My question is really whether, in the context of a major rebuild where budget wasn’t the primary consideration (we are talking north of 10k), most builders would have discussed piston replacement as an option rather than simply reusing the originals if they measured within tolerance.
I completely accept that reusing pistons may be standard practice. What I’m trying to understand is whether my expectation of a rattle free engine following a substantial rebuild is unrealistic, particularly when the builder himself has suggested the noise is likely piston / small-end related, and that replacement pistons would likely solve the issue.
One thing that adds to my concern is that this type of noise seems to be relatively common on 5.0 RV8s. I’ve heard plenty of 5 litres with a noticeable overrun rattle (my previous Chimaera for example) and most owners seem to regard it as a characteristic, despite the fact it is simply worn small ends, the wear exaggerated by the stroke. However, when discussing it with various owners and specialists, I’ve been told it’s far less common on a 3.9, which is partly why I’ve questioned whether it should be considered normal in my case. If 'new old stock' pistons could have prevented this, it would have been nice to know when the build was specified!
Belle427 said:
The million dollar question is did it make this noise before the rebuild?
They are not known for this issue normally.
You sure it's not a lifter or manifold gasket?
No it did not, and yes I am certain it is not a lifter or manifold gasket. The engine builder himself said "it'll be small ends, that's all it can be".They are not known for this issue normally.
You sure it's not a lifter or manifold gasket?
neogeo9 said:
Interested in views from those with Rover V8 engine building experience.
A few thousand miles ago I had my Chimaera's 3.9 RV8 professionally rebuilt by a specialist. The engine is still under warranty and I d prefer to keep the builder anonymous as this isn t intended as a criticism or a naming and shaming exercise.
The engine runs well, makes good power and has healthy oil pressure. However, it developed a noticeable rattle during rev decay and on the overrun at low road speeds days after collection. The builder has listened to it in person and stated that he believes it is likely piston / small-end related, although he is not currently concerned by it.
What has left me questioning things is that I originally took the engine in due to a lifter tick and general wear concerns. Once the decision to rebuild was made, I authorised a full rebuild without hesitation and budget genuinely wasn t the driving factor. I was happy to spend what was required to end up with the best engine possible and numerous upgrades were discussed and carried out during the build. I did not expect the end result to include rattling on the overrun.
What was never discussed, however, was piston replacement. At the time I was fairly green when it came to Rover V8s and simply assumed that anything worth replacing would either be replaced or at least offered as an option. In hindsight, knowing what I know now, I would certainly have wanted that discussion.
So I m interested in hearing from those who rebuild or have rebuilt these engines:
- Is piston replacement routinely offered on a 3.9 rebuild, or only if measurements dictate?
- Is it common practice to reuse original pistons without issue?
- Have you encountered small-end / gudgeon pin noise after a rebuild where the engine otherwise performed perfectly well?
- Given the circumstances above, are my concerns justified, or am I worrying unnecessarily about what is effectively a normal Rover V8 characteristic?
I m not looking to start an argument with the builder, particularly as the engine remains under warranty. I m simply trying to understand what would generally be considered normal practice and whether others have encountered something similar.
Perhaps it may help if you mentioned exactly what was done to the engine during the rebuild process, including how many miles the engine had travelled before the rebuild process was carried out.A few thousand miles ago I had my Chimaera's 3.9 RV8 professionally rebuilt by a specialist. The engine is still under warranty and I d prefer to keep the builder anonymous as this isn t intended as a criticism or a naming and shaming exercise.
The engine runs well, makes good power and has healthy oil pressure. However, it developed a noticeable rattle during rev decay and on the overrun at low road speeds days after collection. The builder has listened to it in person and stated that he believes it is likely piston / small-end related, although he is not currently concerned by it.
What has left me questioning things is that I originally took the engine in due to a lifter tick and general wear concerns. Once the decision to rebuild was made, I authorised a full rebuild without hesitation and budget genuinely wasn t the driving factor. I was happy to spend what was required to end up with the best engine possible and numerous upgrades were discussed and carried out during the build. I did not expect the end result to include rattling on the overrun.
What was never discussed, however, was piston replacement. At the time I was fairly green when it came to Rover V8s and simply assumed that anything worth replacing would either be replaced or at least offered as an option. In hindsight, knowing what I know now, I would certainly have wanted that discussion.
So I m interested in hearing from those who rebuild or have rebuilt these engines:
- Is piston replacement routinely offered on a 3.9 rebuild, or only if measurements dictate?
- Is it common practice to reuse original pistons without issue?
- Have you encountered small-end / gudgeon pin noise after a rebuild where the engine otherwise performed perfectly well?
- Given the circumstances above, are my concerns justified, or am I worrying unnecessarily about what is effectively a normal Rover V8 characteristic?
I m not looking to start an argument with the builder, particularly as the engine remains under warranty. I m simply trying to understand what would generally be considered normal practice and whether others have encountered something similar.
Could it have been more beneficial, to have the engine fully reconditioned.
Gassing Station | General TVR Stuff & Gossip | Top of Page | What's New | My Stuff