This 2.2DCI SpTr Auto has done 73K mls and will be 6 years old soon. It is used for long journeys, runs as it should - probably because of this and it is well looked after by me with 5w/40 synthetic oil changes at 1/2 the specified "intervals".
I would be grateful for advice from a diesel engine expert on when it is necessary to inspect/renew the glow plugs, as this is not specifically mentioned in the service schedules.
My reasons for considering this action are:
1) If I do not remove the glow plugs soon they may become stuck in the cylinder head with the associated problems.
2) They will not last forever and I would rather deal with any replacement before a failure occurs than contend with an unexpected starting problem at the wrong time.
I think that 6-7 years is about the length of service I can reasonably expect from them.
Would inspection reveal whether is is time to renew any?
I welcome advice on this query.
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Hi Fernando. Your correct in thinking that the time for glow plug replacement is nigh, glow plug change intervals are never quoted on service info and people generally dont look at them unless theres a prob starting the motor, of course plugs do more than just start the car, they carry on glowing after starting to assist smooth cold running and by raising combustion temp help to bring your CAT up to heat to burn of cold exhaust gas particles after cold starting, as such they can be made to run after start up for 1 - 2 or 3 minutes by the ECU, the demands on the plug have been increasing over the years as vehicle manufacturers look for faster warm up times in the engine/ ex front pipe and CAT.I have seen engines start well even with 2 inop plugs Ive worked on diesels all my life as a mechanic and found that the ONLY way To test them fully and correctly is with a battery and they have to be removed from the head and tested on the bench, Ive tested plugs in the past with a test lamp that had continuity but then removed the plug and found a heat blister on the element which was ready to drop off into the cylinder. So my advice is to change them now. If your car has been fitted with cheap plugs they will last a mere 15,000. My car was fitted with Beru plugs (a top german brand fitted at new) and at 58,000 miles ( 7 years),... 3 of the plugs had failed causing poor start up, and nasty diesel knock for 5 secs after start up. Plugs are inexpensive (£35-£45 for Bosch or NGK or Beru..set of 4 all top brands)...don,t fit anything cheap in your cylinders and beware of online counterfeits of the aforementioned brands , theres lots about , buy from a dealer or garage... Run the engine till hot, this assists the removal from the head, the hotter the better especially if your head is alloy which tends to grab at the steel plugs, after removal of all plugs, apply copperslip to the threads of an old plug and screw it in and back out of each threaded hole to ease and lube the threads to assist the new plugs ( which will be tight) as they are screwed in, many a crossthread has been caused by over enthusiastically winding in a new plug in a rush. apart from copperslip, an old mechanics trick to overcome a tight thread is too have your new plugs sitting in a plastic bag in ice before fitting,this shrinks the plug very slightly which assists fitting . Apply a small amount of slip to the new plug and Nip the plug up, dont over tighten it ( use a small torque wrench) as this damages the element and after fitting test each plug with a test lamp for continuity before fitting power cables and rebuilding.
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Hi barkas.
I am very grateful for your advice and tips on removing + inserting the glow plugs, which all make good sense.
I believe that Beru g plugs are fitted and I will certainly replace them with one of the makes you have mentioned avoiding online counterfeits.
My main concern was how to remove the g plugs from the alloy cyl head without problems. But I will now ensure that the engine is at working temp and unwind them with great care.
Many thanks again for your help.
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I did the job on a 1.9 dCi Renault of the same year, and found it remarkably straightforward, helped by Renault using push on electrical connections (rather like a spark plug HT lead) instead of those fiddly 8mm nuts.
On the 1.9, it would throw a "CHECK INJECTION" error on the computer (and put the MIL on) if any of the glowplugs were unserviceable.
I replaced the Berus in mine with Bosch items, and had no further trouble in that department.
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