engine rattle

[jon daniels 0]

hi, any one got any ideas?

on slight revs and at high revs my engine has a slight rattle ( a mettallic tinking i suppose) think its comung from the head somewhere maybe left hand side.

i am using the reccomended oil in the book.

maybe thicker oil?

please dont say its terminal but your advise would be nice as first rado

it is an 89 1.8 16v with 130 000 miles.

cheers jon

[jonnyboyo 0]

Could either be the cam chain (not expensive i believe) or possibly the tappets. Again not a an overly pricey/complicated job, but there are 16 tappets at approx £6.50 each (£104), then whatever a new gasket is (not much) plus the labour. Prob be in the region of £200 for having the tappets replaced. Thats what a garage said was a ball park figure some 4 weeks ago.

 

16v's are prone to a tinkling, metallic tappy sound anyway. Its very common and nothing to worry about. Just make sure your motor does not use lots of oil so you can rule out anything more sinister. My 1.8 has 128k on the clock, is a G reg and uses no oil whatsoever, but has a slight tappety sound.

 

Things to try before you plunge into spending on cam chain or tappets :-

 

1) Check that your oil pressure is good enough to supply oil to the top end of the engine. Insufficient pressure will result in lack of oil getting to the cam, tappets etc and cause them to become noisy.

 

2) Try an oil change to a thicker grade, say a 15W 40. A thicker oil has been known to quieten down tappets on some valvers. This being a cheap possible fix and should be one of the first things to do if your oil pressure is sound.

 

3) lastly, try running the car on a high octane fuel such as Shell V-Power, BP Ultimate, Tesco Super etc.

 

1.8 valvers are supposed to be run ideally on a 97 RON fuel, NOT the regular unleaded which is only 95 RON. Lower octane fuel can cause some valvers to "pink" whereas some valvers will run happily on the weaker fuel. Pinking can be characterised by a metallic sound usually heard under load. Again this would be a cheap test do. On your next fill up make sure you have an empty tank and fill with a good quality high octane fuel. Probably Shell V-Power is best for the test.

 

Hope this is of some benefit. I am by know means an expert on mechanics but i do know that it is common for higher mileage valvers to sound tappety!

[jon daniels 0]

thats some really good info thank you, will try that first, having an oil pressure gauge fitted this week too.

cheers jon

[jonnyboyo 0]

Good luck with the diagnosis. Make sure you post up what it was in the end :)

[Dec 1]

"mettallic tinking" could easily just be the exhaust heat shield on the manifold! Tend to disintegrate after a while and vibrate away against the manifold causing a ratting noise!