Problem with engine - help needed to diagnose
Discussion
Few problems with my engine (4.6) that I am trying to get to the bottom of – the collective wisdom of PH would be appreciated. Issues and back story below, engine currently with head stripped and numerous photos. Apologies for length of post but not sure of best next steps….
Back story
No noticeable problem prior to doing body off last summer (write up still to be completed). Nothing done on engine whilst off the car aside from replacing thermostat. Whilst off I noticed a large amount of pink staining flowing down the block from the spark plug in cylinder 5 (and 3 to a lesser extent) along with damp spark plug extender which had pink deposits on.. Consulted a few people (inc specialist) and told no chance coolant coming from there, must have been spilled, and as no issue with engine to ignore it.
Problems
Engine has developed knocking noise which sounds like it is coming from bottom end (although could be wrong) – noise is only there when engine is warm and from idle to about 2500 RPM. The knock increases in speed with engine revs. The only bolts I hadn’t correctly torqued when putting car back together were flywheel (bloody annoying) so had TVR specialist drop gearbox, tighten flywheel and give the engine a look over.
Tightened flywheel reduced noise but didn’t totally remove – specialist couldn’t identify where noise was coming from, had sump and main bearing caps off, nothing obviously wrong. No metal in sump so went with live with it for a while and see what happens.
Noise was staying exactly the same whilst covering a few thousand miles, no noticeable deterioration. More recently it seems to have become louder. The car has also been putting out a large amount of black crap from the exhaust, so much so that I have had to put things up to protect tools from getting covered in it. Again, didn’t do this noticeably previously but has been there since car went back together.
Current situation
To try and get to the bottom of this, I have stripped the engine down. Photos and commentary of what has been found below, hopefully there aren’t too many stupid questions.
• Spark plug extenders in both cylinders 5 and 3 damp and have dried pink deposits. Similar deposits also on spark plugs. Coolant in car is blue so makes no sense at all. Large pink deposit running down side of block
• Spark plugs in cylinders 1 and 2 (frontmost two) covered in large sooty deposits. Cylinder heads also showing large deposits. Remaining cylinders normal in colour.
• Strange deposit in cylinder 4. Soft not hard crystals. Potentially could be a very small amount of the same in the bottom of the sump.
• Bottom end of the engine looks clean and tidy (pistons could do with a clean, front cylinders more so). All liners flush with block – I thought slipped liner was potential explanation – appreciate them being flush doesn’t rule this out. Bores look as you would expect. Engine turns over nicely
• When removing both cylinder heads, a large amount of coolant leaked out, at reasonably high pressure to begin with. This let coolant into the cylinders hence some looking damp. No idea whether this is normal, I didn’t do something I should have done or indicative of a problem.
• Rocker arms – a couple of pads on the rocker arms have significant wear. The remainder have shiny patches but no obvious wear. What to replace?
• Camshaft – haven’t checked condition but was replaced approx. 30k miles ago by previous owner
Oil was very black when drained – only done c3000 miles since last change
Next steps
Not sure whether the best idea is to clean it up, replace worn parts, put it back together again and see what happens or drop the block out of the car and send it all away to the likes of V8 Developments. Unexpected, unbudgeted cost so not in position to go for a full long engine from them unfortunately.
What would you do? What are the possible causes of any/all of the above? Whats the worst that can happen if I put if back together without rebuilding the bottom end? Thanks in advance
Longer term user with problem with original account, not first time poster!
Back story
No noticeable problem prior to doing body off last summer (write up still to be completed). Nothing done on engine whilst off the car aside from replacing thermostat. Whilst off I noticed a large amount of pink staining flowing down the block from the spark plug in cylinder 5 (and 3 to a lesser extent) along with damp spark plug extender which had pink deposits on.. Consulted a few people (inc specialist) and told no chance coolant coming from there, must have been spilled, and as no issue with engine to ignore it.
Problems
Engine has developed knocking noise which sounds like it is coming from bottom end (although could be wrong) – noise is only there when engine is warm and from idle to about 2500 RPM. The knock increases in speed with engine revs. The only bolts I hadn’t correctly torqued when putting car back together were flywheel (bloody annoying) so had TVR specialist drop gearbox, tighten flywheel and give the engine a look over.
Tightened flywheel reduced noise but didn’t totally remove – specialist couldn’t identify where noise was coming from, had sump and main bearing caps off, nothing obviously wrong. No metal in sump so went with live with it for a while and see what happens.
Noise was staying exactly the same whilst covering a few thousand miles, no noticeable deterioration. More recently it seems to have become louder. The car has also been putting out a large amount of black crap from the exhaust, so much so that I have had to put things up to protect tools from getting covered in it. Again, didn’t do this noticeably previously but has been there since car went back together.
Current situation
To try and get to the bottom of this, I have stripped the engine down. Photos and commentary of what has been found below, hopefully there aren’t too many stupid questions.
• Spark plug extenders in both cylinders 5 and 3 damp and have dried pink deposits. Similar deposits also on spark plugs. Coolant in car is blue so makes no sense at all. Large pink deposit running down side of block
• Spark plugs in cylinders 1 and 2 (frontmost two) covered in large sooty deposits. Cylinder heads also showing large deposits. Remaining cylinders normal in colour.
• Strange deposit in cylinder 4. Soft not hard crystals. Potentially could be a very small amount of the same in the bottom of the sump.
• Bottom end of the engine looks clean and tidy (pistons could do with a clean, front cylinders more so). All liners flush with block – I thought slipped liner was potential explanation – appreciate them being flush doesn’t rule this out. Bores look as you would expect. Engine turns over nicely
• When removing both cylinder heads, a large amount of coolant leaked out, at reasonably high pressure to begin with. This let coolant into the cylinders hence some looking damp. No idea whether this is normal, I didn’t do something I should have done or indicative of a problem.
• Rocker arms – a couple of pads on the rocker arms have significant wear. The remainder have shiny patches but no obvious wear. What to replace?
• Camshaft – haven’t checked condition but was replaced approx. 30k miles ago by previous owner
Oil was very black when drained – only done c3000 miles since last change
Next steps
Not sure whether the best idea is to clean it up, replace worn parts, put it back together again and see what happens or drop the block out of the car and send it all away to the likes of V8 Developments. Unexpected, unbudgeted cost so not in position to go for a full long engine from them unfortunately.
What would you do? What are the possible causes of any/all of the above? Whats the worst that can happen if I put if back together without rebuilding the bottom end? Thanks in advance
Longer term user with problem with original account, not first time poster!
Immediate thoughts are liner issues with the leaking coolant and related knocking. How much coolant were you using. ?
Having said that i would have expected to see more evidence of steam cleaning with the associated pistons and combustion chambers, which there isnt.
Sooo i`m going to say like boosted a possible cracked cylinder head.
Having said that i would have expected to see more evidence of steam cleaning with the associated pistons and combustion chambers, which there isnt.
Sooo i`m going to say like boosted a possible cracked cylinder head.
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