tophammer Posted October 13, 2021 Share Posted October 13, 2021 (edited) 2008 ford focus 1.4 petrol hatchback Cylinder 4 Is weak Car cutting out When I go to stop in traffic Code po300 Edited October 13, 2021 by tophammer Quote Link to comment Share on other sites More sharing options...
isetta Posted October 14, 2021 Share Posted October 14, 2021 How have you established cylinder 4 is weak? Eg compression test Or Listening to the effect of disconnecting each plug lead one at a time. Or…. P0300 means misfire on more than one cylinder I believe. If it was only cylinder 4 I think the code would be p0304. 1 Quote Link to comment Share on other sites More sharing options...
DaveT70 Posted October 14, 2021 Share Posted October 14, 2021 26 minutes ago, isetta said: How have you established cylinder 4 is weak? Eg compression test Or Listening to the effect of disconnecting each plug lead one at a time. Or…. P0300 means misfire on more than one cylinder I believe. If it was only cylinder 4 I think the code would be p0304. 26 minutes ago, isetta said: If it was only cylinder 4 I think the code would be p0304. Exactly. First point would be plugs and leads. Then coil pack Then compression test Quote Link to comment Share on other sites More sharing options...
tophammer Posted October 14, 2021 Author Share Posted October 14, 2021 Ahh TK for reply true what u said Tryed everything Even swapped All coyle packplugs leads From other 08 focus Still hunting Then done compression test 4 slynder little bit weak cleared all faults with high spec computer Drove on motorway Not hunting as much But when I slow down Car cuts out Apart from tht Driving as new Just fully serviced and T belt and water pump Last week As u said it's cylinder 4 My mechanic Says drive for the weekend See how it goes But he did say might Be head gasket Or the brain Or valve Any way I can sort this Or will I have to replace With 2 ND Engine What u think tk again for reply Quote Link to comment Share on other sites More sharing options...
F0CUE Posted October 14, 2021 Share Posted October 14, 2021 P0300 Causes (* = Most Common) Faulty or worn spark plugs * Faulty spark plug wires or coils * Distributor failure * Faulty fuel injector Vacuum leak Low fuel pressure Camshaft sensor defective Crankshaft sensor defective Engine timing off Leaking head gasket Low engine compression Poor quality fuel 1 Quote Link to comment Share on other sites More sharing options...
tophammer Posted October 16, 2021 Author Share Posted October 16, 2021 Many thanks for your help Car cutting out When I go to stop or slow down No reading on the crankshaft Etc however done compression test Cylinder 4 is week Is it fair to say I could Put spoon full of oil.down cylinder 4.was told to try slick 50.oil.car is driving fine other than.that like.engine light is staying of.so no fault s .as my friend cleared with.computer .iv done air test etc all is good. Quote Link to comment Share on other sites More sharing options...
Tizer Posted October 16, 2021 Share Posted October 16, 2021 6 minutes ago, tophammer said: Many thanks for your help Car cutting out When I go to stop or slow down No reading on the crankshaft Etc however done compression test Cylinder 4 is week Is it fair to say I could Put spoon full of oil.down cylinder 4.was told to try slick 50.oil.car is driving fine other than.that like.engine light is staying of.so no fault s .as my friend cleared with.computer .iv done air test etc all is good. The idea of putting oil into the cylinder is that if you do a compression test and one or more cylinders is lower than it should be then you put some oil in that cylinder and do another compression test right away. Do not start the engine though because the oil will burn off. If the compression in the low cylinder then rises a lot to a near normal level then the problem will be with the piston rings/cylinder bores rather than the valves or cylinder head gasket. I wouldn't waste my money on slick 50. Your cutting out problem is unlikely to be anything to do with low compression unless they very low. As for what it could be then it is impossible to say from here. Quote Link to comment Share on other sites More sharing options...
tophammer Posted October 16, 2021 Author Share Posted October 16, 2021 What would you say problem is by car cutting out.just as I'm about to.stop just cuts out like Quote Link to comment Share on other sites More sharing options...
tophammer Posted October 16, 2021 Author Share Posted October 16, 2021 Idle What would you say problem is by car cutting out.just as I'm about to.stop just cuts out like. U tube video Idle speed control valve.replacment .might stop from cutting.out . Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Ford UK Shop
Sponsored Ad
Name: eBay
Ford Model: FordUK Shop
Ford Year: 2024
Latest Deals
Ford UK Shop for genuine Ford parts & accessoriesDisclaimer: As the club is an eBay Partner, The club may be compensated if you make a purchase via the club
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.