chazvr 1 Posted September 19, 2011 Report Share Posted September 19, 2011 So the vr hasn't been running great lately...Over the past week on my 40 mile round trip to work the car has been developing a misfire/loss of power for just a couple seconds, then kicks straight back into running normal. This happens once or twice to and from workI was going to investigate this closer this weekend checking coilpack,plug leads, sensors etc when today as i was just about home got the dreaded smell of coolant in the cabin with a wet drivers footwell and steam through the vents.Am i unlucky or can these two problems have any kind of connection? If the car is misfiring would the sudden gain of power when it sorts it self out cause pressure in the cooling system to the point where the heater matrix goes? I've heard of heater matrix failure when headgaskets go. Just gutted as i rely on my vr as a daily driver and have done for the past 3 years and although i think its a great car its turning into a money pit. I've done most of the work on the car up until now including brakes/suspension/thermostat/servicing, but not sure if i can handle this one and a garage isnt even worth thinking about to do a heater matrixI have seen tony's guide in the knowledge vault to do the matrix but is it much more difficult with aircon? Advice appreciated as i dont even want to look at the car right now. Wheres the best place to start?Thanks Link to post Share on other sites
jims13 6 Posted September 19, 2011 Report Share Posted September 19, 2011 No its fairly easy if time consuming , budget a day to do. I can supply the matrix's if you want a quote . Link to post Share on other sites
jims13 6 Posted September 19, 2011 Report Share Posted September 19, 2011 No its fairly easy if time consuming , budget a day to do. I can supply the matrix's if you want a quote . Link to post Share on other sites
chazvr 1 Posted September 19, 2011 Author Report Share Posted September 19, 2011 yer that would be good thanks. what about getting the steering wheel off? Link to post Share on other sites
chazvr 1 Posted September 21, 2011 Author Report Share Posted September 21, 2011 heater matrix arrived today but going to wait until the weekend to start the work. Bypassed the matrix for now to see if i can find this misfire/power loss fault.I checked the plugs which all look ok. Cant see any obvious signs of wear on the leads but could still be a problem?!? and no cracks or arcing on the coilpack. Did leads and coilpack last year but not certain if any could be at fault but visually all look ok. What else can i check? Just want to carry out any visual checks i can do first before i start buying anything. Dont have access to Vagcom either..any help is goood help Link to post Share on other sites
mk1kid 0 Posted September 23, 2011 Report Share Posted September 23, 2011 i have a similar problem at low revs it missfires for about 500rpm and then clears itself ive changed plugs checked the coil pack and leads visually look fine checked the maf looks ok and chacked coolant sensor im stuck too m8 lol Link to post Share on other sites
p0u1 14 Posted September 23, 2011 Report Share Posted September 23, 2011 mate im in bedford i can do the work for you for very little money, i heard garges charging 200-500quid for it, i could have a look at your vr too, im in bedford so if you want a hand send me a pm and i can come see you tomorrow Link to post Share on other sites
chazvr 1 Posted September 23, 2011 Author Report Share Posted September 23, 2011 i got a sneaking suspicion it could be my fuel pump relay as my car has turned over but not started a couple times in the past 6 months and the misfire could be a result of the relay failing further or even the fuel pump. Its a cheap place to start. p0u1 thanks for the offer. Im going to make a start on the matrix tomorrow and try to get it done this weekend. I'll send you a pm anyway so i got your number.Out of the cam, crank and lambda sensor which one could cause a misfire? or could all of them as i think i'll move onto them next.. Link to post Share on other sites
p0u1 14 Posted September 24, 2011 Report Share Posted September 24, 2011 by the way the only sensor to stop my car from starting was the crank sensor on the gearbox side, lamba sensor would just make it run rich but still run Link to post Share on other sites
chazvr 1 Posted September 30, 2011 Author Report Share Posted September 30, 2011 ok..followed tony's guide to get the matrix out. Im at the stage where i should be able to move the heater box out but it wont budge. I've removed the 3 screws that hold the heater box from the bulkhead but it's still feels securely fixed in place.It's got A/C and there are 2 pipes that run into the heater box from the bulkhead but other than removing these I can't see why it wouldn't come out. any ideas on how to undo these? Getting really annoyed at it now..anyone selling a 4mo lol? Link to post Share on other sites
chazvr 1 Posted October 1, 2011 Author Report Share Posted October 1, 2011 disconnected the aircon pipe that runs into the back of the heater box from the bulkhead. Still won't budge. Do i need to cut the strap that runs around the heater box as it looks like it could be holding it in place.. Link to post Share on other sites
chazvr 1 Posted October 1, 2011 Author Report Share Posted October 1, 2011 anyone? Link to post Share on other sites
chazvr 1 Posted October 12, 2011 Author Report Share Posted October 12, 2011 heater matrix now done. Misfire is still present. got new leads and fuel pump relay but its still there. Unplugged maf but no joy but the random misfire still comes. Which sensor do i go for first?..Or is there something more obvious i've overlooked? Link to post Share on other sites
paceo 22 Posted October 13, 2011 Report Share Posted October 13, 2011 heater matrix now done. Misfire is still present. got new leads and fuel pump relay but its still there. Unplugged maf but no joy but the random misfire still comes. Which sensor do i go for first?..Or is there something more obvious i've overlooked?your cat isnt blocked is it causing a missfire?checl coil pack as well for arching. spray a fine mist of water over it at night. Link to post Share on other sites
chazvr 1 Posted October 14, 2011 Author Report Share Posted October 14, 2011 heater matrix now done. Misfire is still present. got new leads and fuel pump relay but its still there. Unplugged maf but no joy but the random misfire still comes. Which sensor do i go for first?..Or is there something more obvious i've overlooked?your cat isnt blocked is it causing a missfire?checl coil pack as well for arching. spray a fine mist of water over it at night.how could i check if the cat was blocked? Theres no arcing on the coilpack/leads. Link to post Share on other sites
oldmandon 1 Posted October 14, 2011 Report Share Posted October 14, 2011 It wont be the cat, If it was blocked, it would stop the car from revving through the rev range, lower revs would be ok, but upper revs no go and a massive loss of power to go with it.Have you cleaned the hall (cam) sensor yet, it's just behind the top corner of the coil pack? This is where I would start if you're happy that the plugs leads and coil pack are fine, as well as the fuel pump and relay. One other area to consider is the injectors, they may be slightly blocked. Run some injector cleaner through and see if that works. Link to post Share on other sites
Daverse 175 Posted October 14, 2011 Report Share Posted October 14, 2011 Have you got a video of it misfiring? that will help us, have you ran it through VAG-COM? that would be best start to point you in the right direction matey.. Link to post Share on other sites
chazvr 1 Posted October 22, 2011 Author Report Share Posted October 22, 2011 It wont be the cat' date=' If it was blocked, it would stop the car from revving through the rev range, lower revs would be ok, but upper revs no go and a massive loss of power to go with it.Have you cleaned the hall (cam) sensor yet, it's just behind the top corner of the coil pack? This is where I would start if you're happy that the plugs leads and coil pack are fine, as well as the fuel pump and relay. One other area to consider is the injectors, they may be slightly blocked. Run some injector cleaner through and see if that works.[/quote']i cleaned the cam/hall sensor just a few months back. The weird thing about it is it will only do it once a journey for a couple minutes then settle. It always seems to happen about 10/15 minutes into my journey tp work then be ok. If i go on an hour drive it will do it after 10/15 mins then be fine for the rest but it consistently does it once a journey after about that length of time. Link to post Share on other sites
chazvr 1 Posted October 22, 2011 Author Report Share Posted October 22, 2011 Have you got a video of it misfiring? that will help us' date=' have you ran it through VAG-COM? that would be best start to point you in the right direction matey..[/quote']hopefully going to get it scanned today. Dont have a vid but will try and sort one out Link to post Share on other sites
Biggazvr6 0 Posted October 25, 2011 Report Share Posted October 25, 2011 Have you got any where with this issue chaz as I'm having same issues as you and it's pissing me off seriously! Link to post Share on other sites
chazvr 1 Posted October 28, 2011 Author Report Share Posted October 28, 2011 Have you got any where with this issue chaz as I'm having same issues as you and it's pissing me off seriously!Yer i've bought a 4motion..problem solved lol. Seriously though it turned out to be the cam sensor mate. Had a read of your problem and sounds like that could be the Maf.Good luck! Link to post Share on other sites
Biggazvr6 0 Posted November 1, 2011 Report Share Posted November 1, 2011 Changed the MAff today for a brand spanker. No better. Still the same. Oh well that's another box ticked of things to change to find the problem! Link to post Share on other sites
filtee 0 Posted November 1, 2011 Report Share Posted November 1, 2011 You should have come and tried mine before buying one and saved yourself whatever it cost. I thought it would have been that . Id be tempted to say lambda sensor next. Not as easy to try one before you buy though with one of those. If you do buy one, id get genuine vag and not one of those universal things. Link to post Share on other sites
Biggazvr6 0 Posted November 1, 2011 Report Share Posted November 1, 2011 im thinking lambda. i can take the maff back or keep it for a spare. i was strugling for time to get to yours pal that was the only thing. how many lambdas are there? are you talking about the one after the cat? all i know is im getting pissed off with it now! if vag specialist dont know whats up with it, ive got no chance. It does smell quite rich tho.......... Link to post Share on other sites
filtee 0 Posted November 1, 2011 Report Share Posted November 1, 2011 If the maf made no difference id take it back deffo.. The lambda bolts into the cat and plugs into the loom. I think in the past they were around 30-40 quid for a new one. Maybe wrong but that price rings a bell. Id get up to althom and get the one off that vr. Pocket sized too which is nice. Link to post Share on other sites
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