Thank you so much. I truly appreciate your knowledge always!
So the MAF reads in kg/hr but on the screen says g/s? Maybe my nano is set up to grams/sec?
Since it seems pretty unanimous that this could be the coils, would it be smart for me to swap the wire from cyl 5 to 8 (cyl 5 is the one that is running rough) to see if the roughness/misfire moves to 8 and then know that its most definitely the coil?
once again, thank you!
Gilbertd wrote:
For the MAF, if you are using a Nanocom, it reads in kg/hr so 26 is a bit high but not by a huge amount. Spec says it should be 20 +- 3kg/hr.
The noise suggests it is running on 7, which you already knew, and it is the mechanical bits moving but not as a result of combustion. I've heard it before and it does sound nasty but will go away when all cylinders are firing.
managed to take a video of the noise.
Like I mentioned only happens on acceleration in drive, neutral can rev as much as you want nothing. I was holding the brakes and accelerating to get the noise to happen, definitely less loud than if you go drive it but can clearly hear it. What do you think?
https://youtube.com/shorts/pAxOSxS3SWo?feature=share
Also checked MAF readings. Cold start was 44 g/s and after 10 minutes was 26g/s. This is pretty high right?
Car also is not loving to start, cranks a couple times before it starts. It is very cold today but I have noticed it had been not as quick to start even when it has been a little warm a few weeks ago
Bolt wrote:
Have a look at the MAF readings since you have a Nano.
Last one I had go out made it look like coils and wires as well.
will do that today, definitely worth looking into.
Thank you Gilbertd and Clive 603!
I am just trying to do the easiest cheapest stuff first. I know that the coil packs were replaced before I bought the car, I have had it for about 15k miles so not that long ago, that said like mentioned parts quality is really poor now a days (have had some really crappy parts lately actually.
I was going to do a compression test next but maybe should jump straight to the coils.
My question is this noise I am hearing ( I will try to get a video of it soon). Its just really strange that only does it when I am driving, Neutral even rolling it will not do it, its pretty loud specially as rpms go up, if just rolling off the accel I can't really hear it. Sounds like different size tools are dropping or something. Got me really concerned if its a sleeve or of course the dreaded HG.
Thanks again I appreciate everyones help here
Hey all,
A few weeks ago I started the car and it was really shakey, knew something was off. After about 5 minutes started hearing a noise, its hard to describe but can't hear it in Neutral, just in drive and after 2k rpm, when I accelerate gets louder. Its not a constant noise, pops are louder and some are not as loud and definitely gets louder the higher the rpms. If I shift to neutral can't really hear it.
Got home and plugged the nanocom, had a lot of misfires, at idle would just go up and up. Had errors p1300, p305 and p300. Checked the spark plug which I had changed earlier this year and looked fine. Changed the coil wire for that one cyl (cyl 5). Started the car and there were no misfires at all in idle on the nanocom. Still felt a little shakey and looking at the roughness tab on the nanocom cyl 5 still constant 2/3/4/5 while others are at zero and once in a while shows 1 or 2. Nothing on the misfire tab. Took it for a drive around the block, at first no further misfires seemed fine however the noise was still there, only in drive if I switch to neutral I can't hear it. Noise definitely concerns me. I also got the car to misfire again, had a few misfires on 5 again, way less and iddle again no more misfires.
I plan on changing all the spark plugs and wires but any advice on what this noise might be? I need to go take a video of it and wish I could hear it in neutral but only while driving around. Could it be the cats?
Thank you all!
Gilbertd wrote:
No idea, a UK car wouldn't bring on the service light for a misfire (or for most other things either) whereas US spec cars seem to bring it on for the slightest reason. Maybe you are just lucky (or a previous owner has fitted a UK spec ECU).
thats really interesting about US vs UK cars.
Well it did bring it up a few months ago, 1 time but since then nothing
Thanks for your knowledge, really appreciate it.
Will update as I drive it more and keep an eye on the live reading of misfires. I still have to replace the wires and so I might just do all the plugs when I do that and will just get NGKs.
Quick question for you. How is it that I am reading a misfire when live reading through the nanocom but then there are not codes being thrown up (neither on the nanocom or through the service light?)
Gilbertd wrote:
Those plugs look to be copper core (fat centre electrode) whereas the recommended NGK equivalent, the PFR6N-11, have a Platinum centre electrode. The first thing I would do would be fit a set of those and see what difference that makes.
I replaced it with another champion and this one does have a platinum center I believe. Going to keep an eye on it but I think you are right, should probably just replace em all and then do ngks (I only replaced cyl 5 plug).
What do you think about the gap being way less gapped? Its almost closed). I am going to pull another one today and look at it and see how it looks.
Finally had some time to pull the spark plug.
Half the ceramic is black, rest is white. Also I noticed that the gap is pretty closed, not much of a gap really.
What could this mean? I have read that could be piston that slapped it close? or could be detonation? (maybe the half black could explain this?)
No codes but when I live read misfires its still doing it but now seems like the cyl that was misfiring a lot is not really doing it and now just getting a misfire on cyl7 but very randomly, get 1 misfire there and then nothing for a while then eventually get 1 again. But no codes at all.
Gilbertd wrote:
Not sure what you are looking at but a leak from the valve cover would be far worse than that slight staining if that is what you ware referring to. What plugs are they? LR suggest Champions but modern Champions aren't the same quality as 20 years ago Champions were. Most of us run NGK plugs.
You've got that horrible SAI system to fight your way past too....
I talked to old owner and he told me that there was no stain there when he did the plugs so this seems to be recent and the cause of the misfire on cyl 5.
The plugs are indeed champions, do you think I should switch that one out to NGK and see what happens? I need to pull it and see how it looks. What other reason could be for that leak?
I have bought some new wires to eventually get these done. Since I am really busy with my job for the next weeks I decided to just get some dielectric grease around the plugs to see if it helps with the arcing (I have half an hour but not more unfortunately). As I unplugged the wires I noticed this around plug 5 (the main offender of the misfires). Looks like either its an old leak (I have asked the previous owner since he did the spark plugs and he woulda noted this) or its a current leak, its almost too much coincidence that it is on plug 5 which is the one misfiring.
Quick search and seems to be probably valve cover gasket? I do still need to remove the plug and look at it, hopefully I can do that this weekend. But I will have to remove the intake anyways to do the wires so would get in there and do this as well.
Harv wrote:
For sure your arcing wires will contribute to your misfire. Wires are very easy to change on GEMS engines (pre ‘99). On Bosch engines some disassembly of the upper intake is usually required (though some people can do the job without disassembly).
Mine is Bosh and looks pretty tight back there :) I will try to not have to dismantle the top of the engine, will use all the tricks in the book but we will see, I don't have kids hands. It will be the first order of business as well as look at a couple of spark plugs to compare to the one that is misfiring.
Also thank you all for the help, I really appreciate it!
mad-as wrote:
hi just a question, did the tick just start or has it been there for a while, it sounds too fast for a single cam lifter. it may pay to take the tappet cover off and check the rocker assembly as the rocker assembly it can pull threads and create rattles which would explain the fast rattle sound you have. your rattle noise is a bit loud and fast for a small nuisance rattle IMO.
Not that long, I would say maybe 3 weeks is when I first noticed it.
Removing the cover is in the future plans if I don't get an answer from the spark plugs and coil wires.
Gilbertd wrote:
The tick actually doesn't sound too bad. I've got 2 P38s (both 4.0) and have just sold a 4.6 and all do it to a certain extent. Mine was doing it when I bought it at 205,000 miles. At 287,000 the engine was completely rebuilt at V8 Developments and when refitted it, it still did it. As it sounded louder from underneath the LH side, I decided it must be from the torque converter or gearbox. At 454,000 miles the gearbox died so that along with the torque converter were replaced. Still does it, no worse, no better than it was when I first got the car.
Thats good to hear (no pun intended haha) but I posted on facebook group and at least 3 people told me cracked block, its over which I think its pretty hard to diagnose through the internet so its good to hear some think it might not be that. I am definitely conducting some tests when I can. First order of business is new spark plug wires to get rid of the arcing which is definitely doing and could be the source of the misfire.
Any recommendation on brand of wires? Right now has STI wire which are apparently pretty popular in discoveries but not sure I should get the same brand, they are about 2 -3 years old.
Harv wrote:
It wouldn’t cause a misfire (unless the leak is very bad and fresh air gets to your O2 sensor). I’m not saying this is your issue, just that small exhaust leaks can present themselves as ticks. Like you did before, you can use your stethoscope and probe around with an exhaust leak in mind.
Thank you Harv. Will poke around this weekend!
Would that cause misfires too though? Also the tick only happens after being warm, would a leak not make the noise as soon as car is started?
What would be a good way to look for exhaust leaks?
Thank you.
Will pull the plugs and look. Coolant seems to be fine. I will say I did have some loss of coolant but I topped it off 3 months ago and seems to have stayed put, I do know I have a small weep on the radiator (have a rad that is ready to go in). I did also check last night and seems like I do have some arcing on the plugs, its minimal but its there when eyes adjust you can see its arcing on all the plugs. I will be replacing the wires for sure.
Have had the p38 for a year now, has been wonderful.
Last week I noticed that after parking and engine cooling down a bit and back on it would slightly shake at idle for 10 seconds then go away. It has been driving fine after that. Also last week got a misfire on cyl 5 (p305 code), the service engine light was on. I cleared the code and has not popped up again (been about 200 miles). It also has been ticking only when warm, it sounds fine when cold and then will start a tick. I got the stethoscope out and its on the right side of the engine but can be heard almost louder on the right side tire well and under the car. Anywhere I put the stethoscope on the right side can be heard. Read the codes today and the p305 was not there but now have a p300 which I know is multiple misfires. I also took it for a drive with the nanocom plugged and it would throw misfires of cyl 5 (but the service engine light has not turned on and when I read codes with the nanocom it shows none)
I have read everything I could on the internet and a lot of cracked block/slipped liner. I want to figure this out myself and see if maybe its not something else because I go into catastrophe mode. Plugs, wires and coils have been done in the past 10-20k miles by the previews owner. Head Gaskets were done about 50k miles ago.
Video of the tick - https://imgur.com/a/p38-tap-I1WRgts
Thank you!