Glow Plugs

[rambler]

Hi folks

In the last couple of mornings my trusty Rav4 has not been so trusty :o

It takes a lot more turns of the engine to fire and splutter into life,and sometimes that yellow light comes on and stays on......

but.....

Then if i turn it off again,let it rest for a few seconds,then re-start the engine..it starts as normal and yellow light goes off straight away..

I did last year invest in a Huge new Battery,biggest i could get,only just fits in the Battery tray :D .....so plenty of power there

Once it is running it runs just fine,no troubles at all

so....could it be 'Glow plugs'...how long do they last please ?

Rav has now done 95'000 miles

[pajjy]

Hi folks

In the last couple of mornings my trusty Rav4 has not been so trusty :o

It takes a lot more turns of the engine to fire and splutter into life,and sometimes that yellow light comes on and stays on......

but.....

Then if i turn it off again,let it rest for a few seconds,then re-start the engine..it starts as normal and yellow light goes off straight away..

I did last year invest in a Huge new battery,biggest i could get,only just fits in the battery tray :D .....so plenty of power there

Once it is running it runs just fine,no troubles at all

so....could it be 'Glow plugs'...how long do they last please ?

Rav has now done 95'000 miles

you can test glow plugs in situ,not sure of your set up but if you disconnect the cable to them one a a time and test with a lamp. connect one end of lamp to batt pos, the other end to the connection at the top of the glow plug then the lamp will light if the glow plugs not burnt out.glow plugs either work or not there is no in between.

my passat lasted about the same miliage as yours but the engine was indirect injection so had to be used every cold start.does your glow plug warning lamp light up and then goes out.it may be the relay.

if you buy new ones,go to a diesl injection specialist i found them cheaper than oem ones and just as good.

[Jamesbelfast]

A test lamp is a rubbish method of testing as it will only prove if a voltage can flow and that is no guide as to the condition or likely performance of a glow-plug. The best in situ., method is to test the resistance of each plug individually - each should measure 0.6 ohms. If there is any variation between them get them replaced.:)

[shcm]

Rambler, please don't take this as an insult, but you are waiting for the glowplug light to go out before starting aren't you?

It's just that I could read your post either way.

Some years ago I was one of the designers for a dedicated glowplug relay control chip within a relay control module. This was before diesel engine management really took off. These days the relay is usually just controlled by the engine management ECU.

Anyway, the pre-heat time is obviously dependant on ambient temperature, 'cause the light stays on longer when it's cold, but the control strategy was to continue to provide power to the glowplugs (and therefore still preheating), even after the light had gone out, for about another 12 seconds (in the case where the engine wasn't cranked). If your plugs are on the way out, Just wondering whether waiting a few seconds longer before cranking, after the light has gone out, might ease things a little as a temporary "stop gap". Probably not, but might be worth a try.

With the engine idling there was also a "post-heat" phase, up to 2 minutes long depending on the application. Possibly there still is.

[stewyinpagham]

I had a Citroen BX that needed 2 hits on the glow plugs in the cold. I would turn the key to the heat position and wait for the lamp to go off, then turn the key to off and repeat and crank as normal. 99% success. This was by far the cheapest option as when it fired it ran clean, not chuggy or only on a couple of cylinders.

[igormus]

Hi folks

In the last couple of mornings my trusty Rav4 has not been so trusty :o

It takes a lot more turns of the engine to fire and splutter into life,and sometimes that yellow light comes on and stays on......

but.....

Then if i turn it off again,let it rest for a few seconds,then re-start the engine..it starts as normal and yellow light goes off straight away..

I did last year invest in a Huge new battery,biggest i could get,only just fits in the battery tray :D .....so plenty of power there

Once it is running it runs just fine,no troubles at all

so....could it be 'Glow plugs'...how long do they last please ?

Rav has now done 95'000 miles

hello mate

a several problems must be investigated before final solution, as follows:

1) glow plugs (all must to have the same resistance specified in the manual);

2) glow pluugs control relay;

3) Workability of your SCV;

4) COndition of fuel filter.

As to item (1) -- it is clear;

As to item (2) -- you ve changed acc Battery -- why??? I ve had the same issue before on previous ford and this relay internal contacts were fully covered by carbon giving an electricity lose + Battery has become flat;

As to item (3) -- these two can also play with you with the same symptoms -- it is an easy to have them tested by multitester whether or not their solenoid coils have good resistance also specified in the manual;

As to item (4) -- it is clear.

Check and revert with investigation details.

Cheers/Igor

[pajjy]

A test lamp is a rubbish method of testing as it will only prove if a voltage can flow and that is no guide as to the condition or likely performance of a glow-plug. The best in situ., method is to test the resistance of each plug individually - each should measure 0.6 ohms. If there is any variation between them get them replaced.:)

the lamp test is only to show the plugs are not burnt out.i doubt if the average owner has the means to test for resistance .dierect injection engines when in good condition will start in cold conditions without the need for glow plugs.anyway after 90000 miles having any doubt about their condition i would treat the engine with a full new set.

i had a 1990 vw jetta diesel with a 1.6 indirect injection,to get a clean start you had to use the glow plug system.i only had it for 3 months (new)when the light failed to come on.took it to the vw dealers to have it checked out and it was the relay that fed the glow plug control system.they did not have one in stock and said they would have to order one,i kicked up a fuss saying as the car was only 3 months old why could they not take one off the 3 new cars they had standing in their yard with the same engine. but they would not budge.as i was working shift work i did not wont to wake the neibours up trying to start the car at 06.00 in the morning i put a feed from the Battery with the help of a suitable cable direct to the glow plug buzz bar for 10 secs and it started ok each time.had to do this for about a week till the new relay arrived.

[Jamesbelfast]

It is possible for glow-plugs to fail short circuit so a test lamp will still illuminate. A basic multimeter can be bought for around 5 or 6 quid which is less than the cost of one glow-plug - plus it can also be used to test if the glow-plug circuit is getting full voltage and for how long.:)

[boilerman]

Hi

I have a similar problem from cold, glow plug light goes out after about 4 seconds, and car is a pig to start, I've tried the on/off method and waited about 10 seconds.... no different.

So, when its cold, how long should the light stay on roughly ??

mike

[rambler]

Rambler, please don't take this as an insult, but you are waiting for the glowplug light to go out before starting aren't you?

It's just that I could read your post either way.

Hi folks & shcm

No worries,yep...do wait for coil lamp to go out,and give it a few more seconds .

The starting sounds different though,more turning over involved and a lot more mechanical ???..,but as i said earlier once it has fired up...on second attempt....no worries

Am almost scared to drive it anywhere ...but it ticking over in driveway at mo sweet as sweet.......after 2nd attempt at starting.no light on now.

I havnt any means of testing the glow plugs,and there are no 'deisel specialists with computers locally',so my earliest i can get a 'fault code' is on my early finish at work on thurs pm, (unless the rav4 breaks down before that) :o

I guess it will be small sensor somewhere.

But would glow plugs allow the engine to run as normal,even after a dodgy start ?

....thanks to all so far

[rambler]

Hi

I have a similar problem from cold, glow plug light goes out after about 4 seconds, and car is a pig to start, I've tried the on/off method and waited about 10 seconds.... no different.

So, when its cold, how long should the light stay on roughly ??

mike

Hi boilerman

Well..i just wait until 'glow coil' has gone out,give a second or two then turn the key...but i never put my foot on the accelerator,i just allow the engine to fire up into tickover.

I always think it gives the 'oil a chance to get around'

[rambler]

Well....i just gave the Rav4 a 'bit of a run' and 'used some diesel',runs absolutley fine,with foot to floor,and on tickover.No malfunction lights...

So its just a longer than usual chuggy starting issue from what i can tell,with the 'malfunction' light illuminating and staying illuminated at first attempt...turn off

Then on second attempt(after about 10 seconds),engine starts as usual and malfunction light goes out (as it should)..runs fine with no troubles and :D

Sorry cant be anymore informative than that....but thats what happens

[shcm]

So, when its cold, how long should the light stay on roughly ??

Probably between 6 and 4 seconds. "After glow time" is how long they are energised after starting. I wish they'd have called it "post-heat".

Rambs as has been said further up, if it is just the glow plugs, they may well be near the end of their useful life anyway.

I think I mis-understood you anyway -sorry. I thought you were talking about the glow-plug light, but I think you are talking about the MIL (malfunction indicator lamp i.e. check engine).

Off on a tangent - Yes, in "theory" direct injection diesels don't need glowplugs. The starting performance drops off rapidly with decreasing temperature though. You might get away without them most of the time in the UK, but the vehicle is engineered for many markets with different climates. If it didn't need the plugs, they wouldn't be fitted!

Yep, a DMM (Digital Multi-Meter)on resistance measurement is just about OK for measuring an individual glow plug. If you are trying to measure 4 in parallel though (by not removing the bus bar), it is probably nearing the limit of accuracy or any meaningful measurement for a 2 wire DMM resistance measurement. I'd prefer to measure current, but most DMMs won't handle that level of current on their own and anyway there is an initial large in-rush current with the plugs cold, which you might want to see, which wouldn't show up on a DMM.

[rambler]

Hi shcm

So.....glow plugs

If the Rav4 has trouble fireing up at first cold attempt,does this not affect the running of the engine after it has fired?.

After all once its running its ok.

(And sorry...yes just relised that both 'glow' and MIL lights are both yellow)

So....if its glow plugs,much much do they cost for full set...anybody know please?

[GS John]

So.....glow plugs

If the Rav4 has trouble fireing up at first cold attempt,does this not affect the running of the engine after it has fired?.

After all once its running its ok.

Not as far as I know. Had a Peugeot 205 diesel and one glow plug failed. A barsteward to start, but one started it was happy. I think that once there's been some combustion then all the gaps / tolerances tighten up, and that's why it'll start easier 2nd time with a dodgy glow plug.

[shcm]

Rambs - I doubt if tired glowplugs would put the MIL on. Perhaps something else related to the pre-longed cranking as a result of tired glowplugs is, but I even doubt that to be honest, but I could be wrong. The stored codes might be useful.

'yer mechanical experts will go into greater detail, but basically as the diesel combustion depends on the fact that squashing the air a lot (high compression) makes it very hot, then adding fuel gives the combustion, once running it will probably be fine. Perhaps a little rough to begin with. The glowplug is just warming things up to start with. Afterwards there is enough residual heat for things to manage without the glowplugs. Although as the graph shows sometimes they can be left on for a while after the engine is running.

The controller I was involved in, in one configuration, would leave the plugs on in "post-heat" mode for a while, if the accelerator wasn't touched.

[anchorman]

In the old Pug engines they had indirect injection and they could be a cow to start without glow plugs.

Rambs. You can get a set for about £40 delivered;

http://cgi.ebay.co.uk/GLOW-PLUGS-(X4)-TOYOTA-RAV-4-Mk2-2.0-DIESEL-NGK-Y-531J_W0QQitemZ390171347211QQcmdZViewItem?rvr_id=175065812521&rvr_id=175065812521&cguid=50eb6fc212c0a0aa16e4cdb4ff8137f1

Most local garages can fit them but I would at least ask them to test them first. It isn't a big job so it isn't the end of the world if you fit a set and it doesn't cure it although it probably will.

They do make a difference to how it starts at this time of year and they do run on after the engine has started but only as an aid to cleaning up emmissions - you could virtually do away with them once the engine has started.

[rambler]

In the old Pug engines they had indirect injection and they could be a cow to start without glow plugs.

Rambs. You can get a set for about £40 delivered;

http://cgi.ebay.co.uk/GLOW-PLUGS-(X4)-TOYOTA-RAV-4-Mk2-2.0-DIESEL-NGK-Y-531J_W0QQitemZ390171347211QQcmdZViewItem?rvr_id=175065812521&rvr_id=175065812521&cguid=50eb6fc212c0a0aa16e4cdb4ff8137f1

Most local garages can fit them but I would at least ask them to test them first. It isn't a big job so it isn't the end of the world if you fit a set and it doesn't cure it although it probably will.

They do make a difference to how it starts at this time of year and they do run on after the engine has started but only as an aid to cleaning up emmissions - you could virtually do away with them once the engine has started.

hi anchorman

So,do you reckon at 95'000 miles these glow plugs need replaceing ?

i'm having code / code's read by my local garage on thur's.So could get them done then.

Actually....i'm suprised that they are not replaced as part of routine servicing..like spark plugs ( cant see them mentioned on service shedules anywhere)

[daviep.sco]

Don't know if this is the same issue or not but my Dad had a similar problem on his old Avensis diesel. It actually turned out that it was the starter motor. He replaced the glow plugs and still had the same problems, after further investigation we found a post saying the the starter motors after about 80,000 miles wear out and need replaced. We changed the starter motor and had no problems at all after that.

Cheers

[rambler]

Don't know if this is the same issue or not but my Dad had a similar problem on his old Avensis diesel. It actually turned out that it was the starter motor. He replaced the glow plugs and still had the same problems, after further investigation we found a post saying the the starter motors after about 80,000 miles wear out and need replaced. We changed the starter motor and had no problems at all after that.

Cheers

Hi daviep

Many thanks for that....sounds a good possibility,as the noise at starting does sound very mechanical (if a starter motor can 'sound' worn out).

But on 2nd attempt if starts just fine

But that could very well be the problem,dont know how much they cost,or how to diagnose it??

Hope to get these fault codes on thurs,maybe that will tell me........I really really hope so,as i miss my 'trusty' Rav4

[anchorman]

Rambs

The glow plugs are just a little heating element that pre heat the combustion chamber. You can't really predict the life any better than doing so for a light bulb. All I am saying is that given the nature of the problem and your lack of test equipment, you could get a garage to test them or at that price just fit a set and start fresh with them. If they are original they have done OK at that mileage!

It was -9C here this morning so all starting problems will be highlighted. In the summer you barely need glow plugs.

[rambler]

Rambs

The glow plugs are just a little heating element that pre heat the combustion chamber. You can't really predict the life any better than doing so for a light bulb. All I am saying is that given the nature of the problem and your lack of test equipment, you could get a garage to test them or at that price just fit a set and start fresh with them. If they are original they have done OK at that mileage!

It was -9C here this morning so all starting problems will be highlighted. In the summer you barely need glow plugs.

Hi Anch's

Well..as usual both your & shcm's opinions are very very welcome indeed,thank you

See what happens this week,off for a coastal days walking now,blue skies here and wide spread frost....beautiful,If rav starts...

And.....it.....did.......no problems....and no MIL light....at the moment & been running for 10 mins now

[rambler]

Hi folks

Well....after my little episode last week of MIL light coming on on two cold mornings, (only -4 :D )

Today i got the fault code......P1228,fuel pump system malfunction ( short). :o

But the light has'nt come on since last friday :D

And the RAV has behaved impecably since then,back & forth to work all week (about 200 miles )no more MIL lights at all :D

Had the code erased now (seemed the right thing to do)

Been snowing here all day,now at about 5 inches ( deep for this area :D )