Hey everyone, I've been dealing with misfire problems on my 2006 LR3 HSE with 115k miles on it for a few months now. I've put in new plugs, flushed the fuel injectors, put in a new MAF, cleaned the throttle body, and the problem still persists. The codes I'm getting right now are p0300, p0301, p0307, p0303, p0304, p0305, and p0316. I really don't want to bring this in to get it serviced, as I know that can add up very quickly while the mechanic tries to figure out what's wrong. Any suggestions?


On a separate note, I'm also getting a low tire pressure warning. I've checked the pressure on all the tires (including the spare) and they are all within the 35-42 PSI range. Should I just start replacing TPMS sensors?


Thanks in advance!

 

Misfires normally occur from 3 sources:

plugs, coils, and fuel injectors. If you have a scanner with real time dynamic data you can look at the misfires than swap coils from a cylinder that is misfiring to one that isn’t and see if it follows. Or do the swap, clear codes and see what returns.

i suspect clogged injectors. You say you flushed them but how?

TPMS, autel makes a tool for around $100 that can read the system, check individual sensors for signal, etc.

 

Thanks Abran, the fuel injectors were flushed by a rover specialist when I had a 120k service done upon purchasing the vehicle around 6 months ago. I'm not entirely sure what procedure he followed, but I've since then not gone back to him because his prices are too high (read dealer pricing). Although I'm fairly certain that he would have done the job right, I'm willing to start with the injectors and move from there. What process do you recommend?

 

I use BG petrospecs VIA. Not necessarily a DIY.

Where are you located?

 

I'm in Central Oregon, I live in Redmond.

 

You can go on BG petrospecs website and find a local shop.

i would try the swapping of coils to rule that out as a DIY diagnostic

 

I picked up some BG44k that I will run through it as a starting measure, and if that doesn't seem to have any effect I'll have to consider bringing it in for a full flush again. Will I have to clear the Check Engine Light to see if the BG44k fixed the problem, or will the light go out on its own if fixed?

I'm hesitant to think that coils are the culprit, as I'm getting misfire codes from so many cylinders and meanwhile the vehicle drives very well, I don't see any loss in power or rough riding. I had an older BMW before that had a coil go bad, and it was very obvious running with one less cylinder. Would the engine still perform seemingly well on the LR3 even if coils were going out? And could one or two coils be throwing this many faults, or could I really have 5 coils going bad all at once?

 

I advice you to pay USD 30 for a blown head gasket kit. I had a similar problem that resulted in that failure. The earlier you detect it, the better

 

Looks like the BG44k did the trick, the check engine light went out yesterday. I'm really happy that I was able to get this worked out, I was getting pretty worried. Thanks for the help guys, I'm glad this ended up being an inexpensive fix instead of really getting into the weeds on diagnostic expenses.

 

BG is good stuff. Congrats