Engine flushers - martin
If it helps anyone considering flushing out engine prior to or with oil change, i used a standard pre oil change flush from Halfords which whilst clearly getting a lot of gunk out of the engine (as was evident from the old oil), did seem to cause one of the Injectors to begin malfunctioning. (perhaps something got jammed in the injector). This was easy to change, but nevertheless am unexpected hassel.

Anyone know what exactly is the big advantage of engine cleaners anyway?
Engine flushers - Dave N
Another £5 in the dealer/garages/Halfords pocket.
Engine flushers - Toad, of Toad Hall.
Martin. I didn't say this earlier because I didn't want to tread on the toes of the site experts.

However I can't think of a single reason flushing oil, or any other kind of oil would block injectors.

As for flushing oil why bother? Just change more regularly or bung some Halfords own brand in for a week and change that.
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These are my own opinions, and not necessarily those of all Toads.
Engine flushers - martin
sure, i don't want to say that the engine cleaner did actually cause the injecotr problem, but it started the very same day. The type of cleaner i used required you to run the engine for 6mins with the product mixed with the oil, but prior to oil change. I thought this could of dislodged something in the injectors? Only guessing!
Engine flushers - M.M
Toad,

I rarely use flushing products....but I will run a fill of cheapish 10-30** through for a few days and then drain it off, re-filling with the proper oil.

**Unless the spec is higher than that anyway.

MM
Engine flushers - THe Growler
Flushing oil I have always felt is dangerous stuff. I have seen engines with no previous problems become oil burners and formerly fine seals start leaking following its use. My old foreman wouldn't hear of it.

Engines "settle" and if all is well and the oil and filter are changed regularly, flushing is unnecessary. Modern oils will take care of the detergent aspect. MiddleMan's answer is a good one, just do a short cycle oil change with a regular oil to clean out if you think you need it, for eample you are changing brands and you want to clear out the last vestiges of the old brand. Of course if you have been servicing the engine for some time and you know the history you will have been changing the oil properly anyway.

Having said that MItsubishi dealers here do flush their diesels at each oil change. However this is prescribed in the manual and they use Mitsubishi flushing oil, so we can rest assured this is OK.

My own inclination is always that old saw "if it ain't broke don't fix it".

Engine flushers - Toad, of Toad Hall.
I rarely use flushing products....but I will run a fill of
cheapish 10-30** through for a few days and then drain it
off, re-filling with the proper oil.


Damn I'm good!

I shall soon be a graduate of the middleman academy...
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These are my own opinions, and not necessarily those of all Toads.
Engine flushers - Cyd
coincidence. the engine oil doesn't get anywhere near the petrol injectors.
Engine flushers - Shigg
From the people I know that drive diesels, most of them swear by using flushing additives, especially before the MOT for the emmissions test. I use them when I first get a car if I'm in any doubt about the previous frequency of oil changes or quality of oil used. That said I used oil flush in my first car (mk2 mini) and all sorts of bits of metal came out, so I now call it bearing flush!

Steve.
Engine flushers - Cliff Pope
If an engine flusher loosened a lot of old gunk and softened the seals and generally caused a bit of smoke and burn off for a while, some of this might get into the crankcaseand then rerouted back through the ventilation system and into the inlet manifold. Throttle valves and vacuum take off nipples do get clogged up with combustion deposits via this mechanism, so it is not inconceivable that something stuck round an injector. Unlikely I agree - I am just musing around some way it could have happened.

I think the general consensus on flushing is that it is OK, and possibly a good thing if the engine is flushed regularly, but a definite NO as a once in a lifetime clear out of old debris - leave it alone.
Engine flushers - 3500S
I've always specified a flush before new oil every six months. The garage I take my daily car to uses Forte (quick plug). I feel it's worthwhile getting anything the filter may have missed.

In the case of the P6, I know it had a rebuild in 1994 and I've the receipts for everything, oil changes every six months in this respect. As for flushing that, a quick word with other owners and they feel there is little point, a mineral based oil, limited mileage, it's not worth it.
Engine flushers - THe Growler
Are we not talking engine oil, and does that have bearing on emissions? Flushing the fuel system to pass the test, yes.
Engine flushers - Shigg
Well yes we are talking about oil flush but it does seem that alot of the older diesels will fail their emissions test if the oil is full of gunk. I guess this could be because of crankcase vent system. My brothers Astra failed a couple times on emissions but following a 'flush', oil and filter it sailed through. It then became routine to service the Astra before it went for the test.

Steve.
Engine flushers - Gazza
Italian tuning helps to sail through emission test too, follows by an oil change.

Garrison
Engine flushers - THe Growler
Well you certainly live and learn. I didn't know that about engine oil and emissions.

(grin) where I come from everything passes the emissions test.

Sir your car appears to be belching over the limit. Would you like me to take another reading? (eyeballs momentarily appear like dollar signs on the slots in Harrah's in Vegas)

Stupid foreigner gets message. You must be hot working out here in the sun all day. Here but yourself a cold drink. (Several cold drinks in fact).

Ah thank you sir, there must have been a faulty reading first time. Your vehicle has passed the test....
Engine flushers - A Dent{P}
Well yes we are talking about oil flush but it does
seem that alot of the older diesels will fail their emissions
test if the oil is full of gunk. I guess this
could be because of crankcase vent system. My brothers Astra failed
a couple times on emissions but following a 'flush', oil and
filter it sailed through. It then became routine to service the
Astra before it went for the test.
Steve.


Seems like another good reason to stay away from diesels.

I have never used flushing oil, understanding them to be bad news and would go along with with Toad Esq and MM if I thought a flush was necessary.

Something I don't get in here, isn't it common knowledge that you do not mix synth and mineral oils?, so what is the flushing oil based on?.
All the oilways and recesses will hold some qty of whatever you flush with and that will dilute and compromise the gold plated stuff you put in afterwards.
To do a flush, do you change the filter twice? or at least drain the old one before using the flushing oil?
Seems like lots of hassle.

A better question might be: How long before the new oil is light brown? if it's only 500 miles, do another oil and filter change at 1000 miles.
Engine flushers - Toad, of Toad Hall.
Something I don't get in here, isn't it common knowledge that
you do not mix synth and mineral oils?,


You *can* mix mineral and synth. It's just a waste of good synth 'cos you won't get full benifit.
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These are my own opinions, and not necessarily those of all Toads.
Engine flushers - A Dent{P}
I personally would not do it, having read Lube Tips for years (industrial lubrication) but I may stand corrected.
If oil is your thing there are whole sites to it..
www.noria.com/message_boards/by_category.asp?Categ...n
Engine flushers - Toad, of Toad Hall.
I personally would not do it,


Why not?
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These are my own opinions, and not necessarily those of all Toads.
Engine flushers - A Dent{P}
The remnants of the flushing oil effectively become an oil additive and if you are relying on the superior protection that fully synth gives you could be in trouble.
The original oil additives protect against oxidation and chemical attack, and are likely to be compromised by the other muck floating around.

I have made a mistake here. Semi synth is a mineral/synth mix so I suppose mixing is not going to kill an engine. The concern should be the limitations of the lesser oil, because when those are exceeded that fluid will degrade the good stuff (one rotten apple syndrome?).

Anyway there is a good deal of tolerance in the whole oil/temp/grade situation and it?s a big subject so I doubt that anything definitive would be decided here, I also note it?s been discussed here before and experiences count for a lot.

My own preference is not to flush with anything other than the regular oil.
Engine flushers - Shigg
Wouldn't have a diesel? Well having driven all sorts of diesel cars and vans for about 14 years to stupid mileages I can't help but disagree. I don't know anybody with a petrol van that's been thrashed 196,000 miles that still started first time, didn't smoke (not burning oil), would pull over a ton and still did 45 mpg+.

Still horses for courses.

Steve.
Engine flushers - Toad, of Toad Hall.
I don't know anybody with a petrol
van that's been thrashed 196,000 miles that still started first time,
didn't smoke (not burning oil), would pull over a ton and
still did 45 mpg+.


Any sales rep!

However as you say horses for courses and it aint gonna do any harm.

I still reckon a quick 500-1000 mile interval with some cheap 'disposable' oil would be as good as flushing.
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These are my own opinions, and not necessarily those of all Toads.
Engine flushers - Shigg
I get your point but with the loads I used to carry maybe the sales rep thing isn't quite as punishing. 45 mpg?

Steve.