Engine wont start

Compression combustion engines are sometimes sensitive to contaminated fuel or the wrong fuel, #2 light diesel can sometimes vary a great deal. When I worked on diesel motors with my dad, the fuel issue was the first thing he taught me to look at when hard starting was the complaint. Cetane ratings should be at the manufacturers minimum rating. Fuel filters should be changed on a regular basis.

My laguna estate 1.9 tdi Disel is having a problem when starting cold.

When i start it it runs with white and then black smoke very lumpy (like it is running on only three pistons plus possible stall time to time plus takes a while to restart after stall ..

All runs fine when warmed up also will not rev over 4000 revs cold or hot.

I have changed the glow plugs and manifold and rocker cover gasket problem still there..

Also there is a sound like a bike pump when ticking over when cold which I can not locate then when warmed up goes away and there is some air bubbles in the clear fuel tube top of the engine.

Sounds like it may have an injector issue.You may want to find a shop capable of testing the injectors and fuel pressure to see if they are all good.Those engines dont like to be run lean or rich, it can damage them internally

Many thanks for your answer took out and cleaned the injectors car running a liitle better will get them checked as sujested again many thanks..

My pleasure

fixed most thing now on my car to try and get it well new problems Getting white smoke now no more black or blue with it just white when i start the car after about 2 mins it goes very lumpy with lots of white smoke then it will stall. restart the car still very lumpy with lots of white smoke but no stall second time round car runs fine when warmed up... Tapping sound at back of rocker cover was located still do not know what it is. if the air pipe is taken the back of the rocker cover the tapping sound is very loud.poss values? This is the same engine in the picture as mine, this is not my engine in my car.mine is cleaner lol.

Also found a other new problem engine managment light will not come on when turn of key before i turn the engine over, bulb checked and fuse all ok take the fuse out car stops running.is it possible my laguna is in get home mode which will exsplain not reving over 4500 revs hot or cold? (just a tought.) rocker cover gasket changed, manafold gasket changed, injectors checked did have oil on two of them now clear, fuel air leak fixed glow plugs new, new engine oil , new fuel filter, new oil filter plus all air pipe taken off cleaned and repaired if needed air filter changed.

Have it scanned to see if the computer will communicate first.White smoke isnt a good sign it can be a mixture issue or coolant burning.Does it use any coolant? especially with it runnning rough, have it chemical tested for a blown head gasket

gear box performs ok until you stop it then goes to get you home (3rd gear gear) if you turn off the engine and restart all is fine untill you stop again can you help? thanks Bob

Hello ... hope you don't mind me adding 2 pence worth jack ! White smoke is a sign of a bad turbo (a common fault on this vehicle) the not revving over 4000 is also a sign of this ... even though the turbo is not kicking in on tick over it will still cause smoke issue's and the ECU will pick up on the fault, plus you are giving it extra gas/petrol (accelerator pedal) to keep/get it going ... Has the turbo ever been replaced ?? It is very unusual on this model for the turbo to last this long ?? you need to have the turbo checked out ... also the check engine light should be ON all the time ... as jack has suggested, have the vehicle plugged into a diagnostic computer to see if it link's and give's any fault codes .. it could be a bad ECU not controlling some of the system's correctly or a bad sensor not giving the correct signal's causing the ECU to supply wrong information ? .. I do suspect the vehicle is in LIMP mode and will need to be plugged into a computer to verify this ? the tapping sound is probably a sticking valve there are hydraulic lifters on this vehicle !! also as jack suggested this could be a headgasket related issue ... have the cylinders compression tested and a chemical test carried out .. if you have bad compression on any cylinders then this could be a sticking valve on that cylinder or a leaking headgasket !! hope this helps .. let me know

Hello .. thanks for the donation .. much appreciated ! You really need to have the car plugged into a diagnostic computer which can check for transmission fault codes .. most transmission repair centre's will diagnose for free .. sounds like you may have a presssure solonoid fault inside the transmission .. but without the diagnostic scan or breaking down the transmission it would be impossible to say !! Hope this helps

Guys thank you for all your input on this matter

I will check the things out you guys have suggested

again a big thank you for you time...

No Problem ..please let us know your final fix .. or repost if you need further assistance ... let us know

Hi guys question for you

If the turbo had gone would it not still smoke even if warmed up with white smoke or is not the case?

reason why i ask car idels and runs ok when warm apart from the 4000 revs problem..

If you are not getting any white smoke when the vehicle is at normal operating temperature then I do not believe the turbo is the fault ... you would get more smoke after warm up especially when pressing the throttle ?... but this is also true of a bad headgasket ? have the vehicle plugged into a diagnostic computer to retrieve any fault codes ! and to check the vehicle is in limp mode ... check cylinder compression also .. hope this helps

Engine Performance problem
1996 Renault Laguna Manual 123600 miles

I'm having a slight problem with my Renault Laguna. the car starts fine in the morning no problem, regardless of how cold it is or how long it has been standing there. However, after about five minutes, when I try to pull away from a junction the engine tries to die. I can stop this from happening by revving the engine with the clutch down. This happen for just a few minutes and afterwards the car runs fine for the rest of the journey. If I stop the car whilst it is playing up or around that five minute mark it is difficult to start (the starter motor turns over but does not fire). I have to leave it for about 10 minutes.
Some time last year I was getting a fuel smell from the engine and through the heater. I have checked the hoses and for leaks else were and all is fine. the smell disappeared after a few days. It returns now and again, but seems very prevalent at the moment. I mention it here as the to problems may be related. Thanks in advance for your help

Hello .. thanks for the donation.. much appreciated

Does the CEL/MIL (check engine light) show at anytime on the dash display ? is it showing constantly ? check the fuel line connectors under the bonnet/hood .. they tend to wear on older renault models and leak slightly and eventually pop off .. let me know

Thanks for the reply. No the 'Check engine light' is not on, nor any other warning indicators. I checked the fuel hoses this morning and I can't see any leaks or cracking, nothing out of the ordinary at all.

It appears as though the fault only occurs when the engine is getting up to temperature. Whilst it is cold or once it gets up to temperature it runs fine.

Thanks again

firstly add a good fuel injector cleaner to the fuel tank ! this sounds like a fuel/air mixture fault .. so you could try cleaning the MAF (mass airflow) sensor .. although the way you describe your fault I would be expecting the fault to be illuminating the CEL ? does this fault occur everyday or is it intermittent ?

MAF sensor uses a hot wire sensing element to measure amount of air entering the engine. Air passing over the hot wire causes it to cool. The hot wire is maintained at 392°F (200°C) greater than ambient temperature, as measured by a constant cold wire.The current required to maintain hot wire operating temperature is proportional to the intake air mass. The PCM uses this current requirement to calculate the fuel injector pulse width in order to provide the desired air/fuel ratio.

Thanks for the reply again Dave. Yeah it happens every time I use the car, just as the engine reaches optimum temperature. You can set your watch by it, it's got to the point I know exactly when it is going to happen.

I'll take a look at the MAF sensor, thanks again

You were spot on with the air flow sensor, the car is running fine now, thanks. All I need to do now is sort out the petrol smell. Thank again

No Problem ... The only thing i can think of with the petrol smell is the problem all renault's have with the fuel pipe connectors (plastic connectors) .. they were always popping off or working loose now and then ...also some models have a fuel filter located under the vehicle behind the bottom sill near fuel tank !! the connectors could be loose there ? ..it could also have been the vehicle MAF sensor was correcting the fuel overly rich (adding more) and this was causing the smell !! let me know if the problem persist's ....hope this helps ... please spread the word of our assistance .. feel free to use the feedback portion at the top of this post !!!

Happy Motoring
Dave H