DOYLEY Posted May 23, 2017 Report Share Posted May 23, 2017 Hi Guys, Does anyone have a view what are considered reasonable cylinder compression levels should be on a TR5 (80,000 miles on the clock) Getting some varied results across the pots. Many Thanks Doyley Quote Link to post Share on other sites
stuart Posted May 23, 2017 Report Share Posted May 23, 2017 Varied is a worry depending on the difference, what have you got? Stuart. Quote Link to post Share on other sites
RogerH Posted May 23, 2017 Report Share Posted May 23, 2017 Hi Doyley, how did you take the readings.? Roger Quote Link to post Share on other sites
DOYLEY Posted May 23, 2017 Author Report Share Posted May 23, 2017 Hi Guys, Took the readings with a compression tester, - a pretty good one. ( from a good mechanics workshop) We have got compression readings of 180 - 150 across the line. I think we should be looking for between 155-165? My senior spanner scientist is going to have a looks at the valve timings tomorrow, he was muttering that sometimes you can slip a sprocket. ( think he's referring to the timing chain, which would mess up the valve opening and closing, as I understand it) Getting a bit passed my limited knowledge but thank you for your replies to date, much appreciated. Regards Doyley Quote Link to post Share on other sites
john.r.davies Posted May 23, 2017 Report Share Posted May 23, 2017 As Stuart implied, there is no absolute number to look for. Compression testers are neither precision instrument nor calibrated, but good to compare the compression across the block. Should be less than +/- 10psi, so 150-180 not good. Try the oil test to diagnose the leak. A teaspoon of engine oil in each down the plughole before repeating the test. If the compression doesn't rise significantly, then there is valve leak, as the. Oil will help zeal the rings. Quote Link to post Share on other sites
peejay4A Posted May 24, 2017 Report Share Posted May 24, 2017 (edited) You won't have slipped a sprocket without major damage to the timing wheels so discount that. Did you have the throttle open doing the test? How many revolutions, what's the state of the battery? All other plugs out? Borrow a leak down tester to get a more comprehensive diagnosis and as John suggests above, do a wet/dry comparison. Post the results for all the cylinders because adjacent low pressures can indicate head gasket failure. Edited May 24, 2017 by peejay4A Quote Link to post Share on other sites
RogerH Posted May 24, 2017 Report Share Posted May 24, 2017 Hi Doyley, of course you used a compression tester but how did you carry out the procedure - ref Peter's post above #6 Actual values are less important than consistent values - 150, 150 is better than 150, 180 etc etc. Roger Quote Link to post Share on other sites
DOYLEY Posted May 24, 2017 Author Report Share Posted May 24, 2017 Hi All, Well after another day, we have established a sticking valve.... Thank you guys for your comments and knowledge... Onwards and Upwards............ Regards Doyley Quote Link to post Share on other sites
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