Engine Flushing?

[pstruckers]

Hiya folks,

Another query in my quest to get my Renault 4 in tip-top condition. What's everyones thoughts on engine flushing? The engine has done about 150,000 and I though it couldn't harm to do an oil change and combine the work with a good engine flush?

Whilst the car runs fine I am also replacing the spark plugs/leads/condensor/points/oil filter/air filter/fuel filter and rotor arm as a matter of course.

 

[reidalpine]

engineflushing beieng a good idea,and should be done whenever you change oil.Pour in the flushing-stuff and follow istructions-Either take it for a spin or let it run on slightly high tickover untill thorougly warm
then drain all goo be sure to place so that All goo will come out.
Always change oil-filter at this point so no flushing-stuff remains inside as this could play havoc as it is So effective it makes it hard for oil to stick to surfaces where it's imperative..
Engine should -In my opinion,be flushed every time you change oil/filter (it's a cheap form of insurance!)
If you have looked inside the oilpan or valve-cover you know it usually looks a mess so go for flushing every time! -R.

 

[Steve Hennessey]

Mmmmmm - have to partly disagree. If the car has done 150,000 and you peek inside the oil filler cap or remove the rocker cover and find plenty of gunge then a flush would not hurt. Remember that flushing oil will only remove engine 'cholesterol' from the oilways and some gunge from elsewhere. It's unlikely to make the insides of the engine so clean that you can eat from it!!!
High tickover is more preferable to taking the car for a run as no load will be put on the engine. Leave it ticking over for about 30 mins and then drain, remove the oil filter and discard. Leave a container under the sump all night so virtually all the flushing oil will be drained off.
There is absolutely no need to flush at each oil change. Regular annual or 6000 mile oil changes with a good quality oil will be enough.

 

[reidalpine]

Hi Steve! I've never had an engine seize on me so I'm looking at flushing as a cheap form of insurance.As I am seing flushing out the cooling-system..
The role of oil isn't just to lubricate but also to transfer heat and particles away from mating surfaces.
With lots of starts and stops the oil accumulates Lots of pollutants/
particles/soot/water etc. but I am not saying my opinion to be The
ultimate.
I've also seen several opinions re.engine-treatment (Teflon etc)some say these old(er) engines were built to larger tolerances so engine-teratment or even synthetic-oil would ultimately ruin them as modern oil and Teflon too are too efficient and a washing away of the oil-film on coarse surfaces could be the result...
My opinion is that you can Never use Too good an oil!
I've treated (old)engine and gearbox plus wheel-bearings with PTFE-Teflon (on 3 different occasions) and on treating the wheelbearings after initial 'run'in period' saw a 100% roll-out.
On my motorcycle saw a HUGE rise in tickover!!
this was an approximate test-using same known road I sped up to 100km/h then shited into neutral let the car roll untill it slowed down to 80km/h and measured the distance by tripcounter..
After engine terated it was much easier to start.Only neg.effect was the heater didn't produce any heat so needed to cahenge thermostat.Due to loss of friction I would guess.
Gearbox shifted easier and was quieter too.
They advertice with lot better petrol-economy..This I am more unsure of I saw - on accation- a reduction of 10-15% but that wasn't what I was after so I see it as an added 'bonus'

 

[Melc]

Here Here

My 4's are the old ones and do not have filters, this makes oil changes critical to be done regularly. With the contrasting opinions that you get on flushing, I thought, with a bit of experienced help, that multiple oil changes, instead of using flusher, is safe and will clean the engine.

The way I have done it has been to change the oil, run it for half a day, change again and repeat until oil is golden. The bonus is that the 800 motor only uses 2 litres for every change, and the car that I have done this with is clean as a whistle.

 

[reidalpine]

G'Day Melc! Yours is also a very good idea as you get the extra cleaning by changing oil twice,but how many does this? If you use engineflushing it's all One operation.but every man to his horse!
Guess you have a bit more heat down there so that might account
for the oilconsumption.Roffen has so far not used oil at all between
changes. watch that roo! -R.

 

[ggcton]

flushing oil

I am new to the R4 but have a few other old Renaults.
In most of the factory documents it said on no account use flushing oil.
I have found frequent oil changes are the best way.I recently bought a 4cv where the engine was black. a few changes of the oil brought things back to normal. Remember a lot of the older Renault engines were looking for oil changes at 3000 miles as they had no filter.
Gary

 

[Steve Hennessey]

In engines without filters (must be pretty rare to find these now) using a good quality brand oil for half a day is fine before replenishing with clean oil.
However, I have never used flushing oil in any car I have driven and I always get extroadinary mileages!! Maybe because I change the oil on the dot.
I have tried Slick50 (teflon additive) in one car and have to admit that the engine was quieter and smoother - this was in a Citroen GSA. Some people will argue that the oil filter removes the teflon particles straight away so no benefit is gained - who really knows??
In my early days as a mechanic molyslip was the favourite. Those were who unfortunate enough to buy a Ford Anglia or Cortina with the 3 main bearing engine used to chuck this additive in to try and take up the huge amounts of wear that occurred on the bottom end in a relatively short period of time with little success.
Having stripped a 688 engine and seeing the bulletproof crank, no additive is needed at all. Maybe, just maybe the earlier engines could do with a little help so out of all the additives I would go for a teflon based product first.

 

[paulandpat]

An ex colleague who ran a Bedford CF petrol as a parcel delivery van - must be the best part of 25 - 30 years ago now - swore by flushing out the engine with paraffin every 2 oil changes - he would get home from work on Friday evening whilst the engine was still warm from 200 miles and up to 100 stops, drain the oil, change the filter, fill up with paraffin (not sure I've spelt that right), run the engine for about 10 minutes whilst he had a cup of tea, drain, then refill with fresh oil. He reckoned on getting no engine problems - he also managed 400,000 miles in a Mercedes 307D with no problems!!!!

 

[pepper]

I've used flushing oil in an old Scirroco I had years ago, it was the worst thing I ever did to the poor engine, (it had done 198,000 miles) once I flushed it, it wouldn't hold oil pressure at low revs anymore and the engine deteriorated quite badly and I had to replace it a 1000 miles later, I've never used it since and have run other cars upto the 250,000 mile point, I believe regular oil and filter changes with good quality filters and oil (Purflux and Morris's for me) are the way I work.

 

[Melc]

If you use engineflushing it's all One operation.but every man to his horse!
Guess you have a bit more heat down there so that might account
for the oilconsumption.Roffen has so far not used oil at all between
changes. watch that roo! -R.

Tally Ho R,

This system could be done in one go but if people dont want to chance the amazing chemicals that are in these flushers, the more times done, the cleaner the engine. i am sure that this theory will work with a flusher as well.

And that 2 litres is the amount of oil that you need to perform a change, not what my car uses between changes. Sorry about the ambiguity, the 800 motor is amazingly good for not using any oil.

Melc