How to check valve clearances and adjust it, on at HDI engine?

Very complicated I would think. The old XUD required removal of the camshaft, then removal, measuring and replacing of shims. There are grave warnings about interfering with hdi's. There's a lot of pressure in the fuel system.(Like 50,000psi). DaveK.

Hi,

Thanks,

Is there no easy way to do the adjustment, with help from some special tools?.

It sounds a bit expensive to remove the camshaft ect. to do the adjustment.

TIH

Once again, they're hydraulic tappets and cannot be adjusted. If noisy, renew. They don't seem to give too much trouble though.

Hi,

I was told that the valve clearance could, and should be adjusted it my car has starting difficulties.

So you are telling me that this is not possible?

Stange!

TIH

You were misinformed This engine has hydraulic tappets and are self adjusting. I believe it is only the TU engines single cams that are able to be adjusted in the current range of cars.

The HDI engines have hydraulic selt adjusting tappets.

The single cam TU engines have rocker arms, where the valve clearance can be easily adjusted by a screw on the end.

Only option is to replace the tappets, although I would get a second opinion on this as they dont usually give too much trouble and are a big job to replace.

Is the engine noisy? Can you hear the tappets?

Hi,

No there is no abnormal noise, but I have the following problem with the car. I was told that the valve clearances could be the cause of the problem.

My 406 HDI has some starting problems.

About 2 weeks ago it refused to start (but turned the starter motor ok), I changed the glow plugs, diesel filer, cleaned all electrical connectors in the engine bay, check all fuses, replaced the pressure regulator on the back of the pump, cleaned the valve on top of the pump, checked the return valve on the supply to the high pressure pump, checked the fuel supply from the lift pump and cleaned the connector on top of it, checked the fuel flow from the high pressure pump to the rail.

I still have the same problem!!!!!!!!!!!!.

Normally when I want to start the car with a cold engine, I just turn the key and the car starts after 2-3 seconds, but now the car needs a lot longer time before it fires, about 5-6 seconds with the starter running, sometimes the car will not start at all.

But the weird thing is, when the engine then starts it runs normally, responds to the accelerator normally.

I thought about replacing the pressure sensor on the rail, or the valve on top of the pump.

I checked again, and the fuel lift pump delivers a very constant flow of fuel to the high pressure pump. I check the ground connections to the ECU and the engine, and found no problems. I verified the adjusted the camshaft sensor, and found nothing wrong.

I checked the flow of fuel from the high pressure pump to the Rail it self, by unmounting the pipe from the rail. The flow of fuel from high pressure pump was constant, but significant slower then the flow from the lift pumps.

Is that correct? Or do I have an indicator that something is wrong with my pressure pump?

How does the pressure sensor on the rail and the pressure regulator on the high pressure pump work together? Has anybody had problems with these to sensors?

I need some advice, to continue my troubleshooting.

TIH

Hi mate, first of all this vehicle is a high pressure direct injection engine(not in-direct) so glow plugs only HELP warm the cylinder a little (at 0 degree's c supplied for 0.5 sec) not much! ,and have no bearing for a none/hard to start vehicle. usual things for a none starter are pressure probs i.e low pressure pump in tank which should supply 2.5 and give 0.7 return pressure in bar. once you have disconnected the pipes you are supposed to replace 'em as they leave a "foot print" and under the high pressures this engine uses (298 idle upto max 1350 bar) so be carefull.other things are fuel pressure sensor (x3 way red on rail disconnect to give a default value ) injectors leak off , and last of all if everything on h/p side is ok the high pressure pump (min 120 bar to start ) personally though b4 you condemn that whack on a p-codes reader just to make should you have no other electrical faults present.. n e way all the best in your dignoses. mark (peugeot master technician)

Hi Mark,

Thanks for your information.

What do you mean by:

"other things are fuel pressure sensor (x3 way red on rail disconnect to give a default value )"

Do you mean that the pressure sensor on the rail needs calibration, and that this is done by disconnecting it?

Do I disconnect it and switch ignition key to position 2?

I think my HP pump is ok, because when the engine is running everything is normal. The Car runes like a dream.

TIH

I think the best thing to do would be to arrange for a fault code reader to be used on your ECU. If this comes back clear, try checking there is sufficient compression in the cylinder by using a compression tester or even a leakdown test. This 'may' higlight any issues with valve clearance/followers.

what i mean is if you disconnect it ,it will give a default value to the eng mang e.cu (in case you have a duff one) as obviously this will give info to adjust injection duration to the e.c.u .? you dont need to calibrate this sensor at all.By all means do a compression test as advised by others BUT in my experience valves NEVER cause this type of fault on this engine type . any info n/p please ask ,all the best mark.

Hi Mark,

ok, today the car had starting problems again, after cranking the starter for 3 minutes with out starting, then I disconnected the x3 connecter to the pressure sensor on the Rail it self.

Then I tried to start the engine again and it started after trying for 4 sec. almost a normal start, but it was like the engine had a hard time gaining rpm.

Then the engine management light of cause came on, and the display said ?Anti Pollution Fault?, while the engine was running I connected the red x3 connector to the pressure sensor again. I then drove the car non stop for about 200KM with out any problems, driving at about 140km/h on the highway. I the reset the engine management warning, by disconnecting the battery for about 1 hour, and the connecting it again and starting the car without any problem, and with not engine management fault.

Intact I changed the pressure sensor on the rail just one week ago, so I don?t thin it has anything to do with this sensor.

Mark you wrote earlier, that when I disconnected the connector to the Rail sensor, the ECU would adjust the injection duration, what else could effect this?

TIH