skeggyrik 3 Posted January 16, 2007 (edited) While I'm in the process of doing everything else and before I do the cambelt I want to do a compression test as a quick check. If something's a miss I'm in a better situation to do something about it now rather than when everything is back on the car. I've not done one before but I have done some reading on what's involved, not much. Read about the squirt of oil trick to seal the rings to check for a leaky valve as opposed to ring wear. I'm told I should ground the plug I've taken out, when testing. Any other tips welcomed.. It's an Mi not that it should make any difference. Anyway, I need to buy the kit. I've seen one at screwfix for £16.50, any other suggestions, before I go an buy it? Unless there's anyone near me willing to lend me one? Edited January 16, 2007 by skeggyrik Share this post Link to post Share on other sites
jackherer 543 Posted January 16, 2007 dont ground the plug, unplug the LT connector on the coil to disable ignition totally. Share this post Link to post Share on other sites
hengti 2 Posted January 16, 2007 not sure if you haven't already, but this is an interesting read : http://www.pumaracing.co.uk/comp.htm hopefully i won't be h,d&q'd for linking to that without permission .. Share this post Link to post Share on other sites
GLPoomobile 958 Posted January 16, 2007 dont ground the plug, unplug the LT connector on the coil to disable ignition totally. There's a far chance I'm being thick, but I'm sure when I did this the engine just refused to turn, so I had to plug it back in a just ground it instead. Share this post Link to post Share on other sites
tidypug 5 2 Cars Posted January 16, 2007 i found it best to remove all the plugs, remove the fuel pump relay so you don't get loads of fuel in the bores, and also have the throttle wide open when you turn over the engine. Share this post Link to post Share on other sites
jackherer 543 Posted January 16, 2007 There's a far chance I'm being thick, but I'm sure when I did this the engine just refused to turn, so I had to plug it back in a just ground it instead. don't know how you managed that? Share this post Link to post Share on other sites
skeggyrik 3 Posted January 17, 2007 (edited) Thanks for those responses. Dropped screwfix option as on inspection it was rubber bung type. Will get the screw in type from halfords. Will drop the LT off coil, much easier and gives me another hand to work with. Hopefully I'll not be back on here with suspicious readings. Hoping for 195psi across the board! Doubt it though. From reading previous post I see 190+ psi is a good sign with no more than 10psi between cylinders. Does anyone know the official stated range for a static test on the Mi? I've only got a 205 haynes. Edited January 17, 2007 by skeggyrik Share this post Link to post Share on other sites
smckeown 1 Posted January 17, 2007 I found videoing each test useful, as you are looking for multiple things in order to interpret the results. The puma page is very useful. Share this post Link to post Share on other sites
skeggyrik 3 Posted January 17, 2007 I've read through the puma page, as above, very useful. As for videoing it, that would be useful to show differences in the time it takes to "get up" to pressure I presume. A few seconds difference here or there between cylinders may not be immediately obvious whilst performing the test. Share this post Link to post Share on other sites
smckeown 1 Posted January 17, 2007 yep, search and you'll find my recent vid Share this post Link to post Share on other sites
