engine spluttering

[donmar]

Hi I am looking for help, last week my car started to miss fire when engine got to normal temp, which to me felt like a plug down so I changed the plugs and HT leads but still does the same some time it clears other time it don't, but it engine runs fine was it is cold, I didn't change the coil packs as they cost £160 each unless I go for after market which I don't fancy and I think anyway if it was one of those it would be miss firing even when cold, could it be the MAF sensor any help or advice welcome.

many thank

Don

[Bluesman]

May well be be your Mass Air Meter need cleaning. Mike.

[donmar]

cheers mike, so could it make that happen when hitting normal temp and is there anything else I should look at ?

 

[steve2006]

Even if the EML isn't on there may be fault codes stored so have them read before doing anything else, thermally affected causes could be the CTS, CPS, and as you mention a coil pack.

Did you check the electrical connection plugs on the coils, they tend to become brittle with age causing poor connections.

[madfish]

To me it sounds like a coil pack.

Had the same issue on a previous car, onl y happened when engine warmed up.

I would suggest trying to find a second hand one and then go about swapping out coil packs one by one to try and find the offending item

[donmar]

11 hours ago, steve2006 said:

Even if the EML isn't on there may be fault codes stored so have them read before doing anything else, thermally affected causes could be the CTS, CPS, and as you mention a coil pack.

Did you check the electrical connection plugs on the coils, they tend to become brittle with age causing poor connections.

thanks you, I got MAF cleaned still the same the coil packs looked ok but you never no, I ant got no lights on dashboard had a  chap out yesterday it was ticking over for over an hour on my drive and didn't miss once put is diagnostic on and no faults found, but its like I said to him it only happens when driving and hitting normal temp then it start to miss fire, I didn't want to get coil packs but I think I will have to

[donmar]

update, well I did fit new coil packs and still the same having a diagnostic done on Friday morning now hopefully they can find the fault

[messi]

Could it be fuel related? Do you use cheap supermarket fuel, if so, fill it up with v power shell fuel and give it a good drive on motorway and see what happens? 

[donmar]

7 minutes ago, messi said:

Could it be fuel related? Do you use cheap supermarket fuel, if so, fill it up with v power shell fuel and give it a good drive on motorway and see what happens? 

I think it is to do with fuel related and I have used the same fuel station for 40 years so I don't think it's that and I wouldn't trust it on motorway the way it is, when it happens it feels like a plug or 2 down that's why I went right to the plug and HT lead change and then the coil packs ? It ran fine upto 2 weeks ago and just started to judder as if it was going to stall, I have got a problem with ABS on back and LEXUS have told me that could be the problem, I Can't take to them as I can't trust the car getting there so I am having someone come out on Friday to do a diagnostic as the plugs leads and coils cost me £300 to buy so I have to stop guessing what it may be, it could be fuel pump and filter but as I said need to stop spending on maybe

[Mike246]

Donmar, I can tell you exactly what the problem is. In fact I would put a tenner on it and give odds.

The issue is your Oil Control Valve (OCV) which is located at the top of the engine and at the front. The mesh filter gets clogged and the solenoid valve sticks, giving incorrect camshaft timing.

The valve is straightforward to remove (although I got my mechanic to do mine) and clean. Ideally this should be replaced but a clean-up will prove me right.

Those of us with '98 GS300's must pull together to keep them running! Even by Lexus standards this model is a gem.

 

[donmar]

On 4 April 2016 at 4:49 PM, Mike246 said:

Donmar, I can tell you exactly what the problem is. In fact I would put a tenner on it and give odds.

The issue is your Oil Control Valve (OCV) which is located at the top of the engine and at the front. The mesh filter gets clogged and the solenoid valve sticks, giving incorrect camshaft timing.

The valve is straightforward to remove (although I got my mechanic to do mine) and clean. Ideally this should be replaced but a clean-up will prove me right.

Those of us with '98 GS300's must pull together to keep them running! Even by Lexus standards this model is a gem.

 

Thanks Mike I will have a look at that if I can find it, anyway update is as you know I put new plugs and HT leads on then I fitted coil packs and then a diagnostic which said bank 1 and bank 2 co2 sensors so I got new ones bank 1 and 2 and the one underneath drivers side on y section exhurst and guess what the exhurst is fractured around the sensor and also the flange letting in air? Which is the course and I got the exhurst done on Friday and the car now is running fine