Engine flush

[Linas.P]

Hi all,

Just wanted to hear some opinions about engine (oil) flush. I have seen few people said they have done it on IS250 and they have good results.

I was never big fan of this stuff as it is not standard procedure and are not required unless there are certain situations where engine gets gunked-up for some reason e.g. sticking valve lifters. Then there are some horror stories as well... and I guess for a good reason. Generally, if engine was neglected for long time, flush can raise all the dirt and circulate it around the system, which is obviously not good. As well if engine is old and gaskets are just holding on actual gunk... cleaning it might blow the engine. So for a while my opinion was that regular oil change should be sufficient, especially if one uses premium oils (which has all kinds of additives).

When it comes to my engine I "believe" it was never neglected. It is high mileage, but does have FLSH and since I have bought the car (last 30k miles) I was changing oil every 5-6k miles. The only unknown is the very first oil change from the dealer who sold it to me (non-Lexus), as they did change the oil in front of me, but after 2-3k miles it turned quite dark - I know it is normal to certain extent, but it was more than that. Now this could indicate that engine was neglected, but again based on service history that is not the case, last service was done like 3k miles before I bought it and it was just the case that car was on sale for one dealer to another for around 5 months, so dealer agreed to change it not because of the miles, but simply because of the time and peace of mind for me. So then I though... because last 2 changes were very low miles I might pull 10k miles, but after 7k engine started rattling when cold and under acceleration (I believe sticking valve lifters) and I did oil change straight away and rattle was gone for a while.

Maybe only 2 points to highlight here... From service history I can see that at some point Lexus had put wrong oil.. That was Castrol GTX 5w30 C2 (not even fully synthetic) and later Mobil 1 5w30 C3... Finally, seller put some no name 5w30 from the barrel, so I am not sure what was that - barrel had Shell Helix on it, but nobody can tell what was inside... maybe rapseed oil from local grocery. As all were 5w30 I believe difference is very little and could not harm engine much... but who knows.

Now few weeks ago I have ~6k miles since oil change and engine started rattling again. So I have changed the oil and rattling is gone again. However, ever since the first time I was considering engine flush to make sure engine is clean. As well oils like Castrol Magnatec or EDGE are bit of overkill for this engine especially considering my frequent changes above recommends service intervals, so I would expect it to last much longer than 6k miles, or especially I would not expect any rattling. So I kind of think that for some reason my tactics so far doesn't work.

Additionally, I know that engine flush is one of the best ways to clean sticking valve lifters and eradicate rattle, so it sounds like perfect solution. However, there is one caveat - when the guys were changing oil I have checked the old one and it had little bit of petrol smell... Obviously, that is not great, but it is high miles’ engine and it was nothing excessive and finally I don't know maybe they used to keep petrol in that pan. But you know my paranoid mind now wonders, maybe the head gasket is on the edge of blowing and I just make it worse when flushing the engine...

Finally, from reviews and recommendation it seems everyone recommends Wynn's flush. I don't know if that is because it is actually good, or because it is cheap. What you guys use and do you see any difference between the brands, what do you recommend? Many thanks in advance...
 

[Verbout]

You're going to get as many fans as you are detractors.

Never felt the need to flush any engine, but someone will be along who has always flushed and that will explain why his/her car is now on 3,000,000 miles

I go along with the auto box theory, similar to what you mentioned:

You may disturb some crap that was doing no harm, on the other hand you may not.

[Linas.P]

My only reason is those sticking valve lifter ... obviously I only suspect that and it might be something else, but all symptoms matches.

And two is that I am surprised about that happening after only 6k miles, whereas I believe I change oil early and no such thing should happen.

[Verbout]

Thinner oil, STP type additive, have you considered that?

Or....http://www.halfords.com/motoring/engine-oils-fluids/fuel-oil-additives/wynns-hydraulic-valve-lifter-350ml

[is200 Newbie]

I will be the first along to comment on the use of the engine flush...I regularly do it - twice a year along with the oil change. It is a personal thing I guess. My use started when I owned a Vauxhall Astra and the engine rattled like hell - I tried the engine flush and it quietened it down quite a bit but shortly after I got rid of the car so cant comment on it totally eradicating it on another brand or car.

Since then I have used Wynns flush at every oil change on the Lexus. The rattle you have noticed I had experienced a long time ago when I first got the IS250. After a few oil changes and engine flushes I can only presume that the noise disappeared due to this fact as I was not doing any other maintenance to resolve the noise. The noise, if its the same, sounds like a machine gun for a second or so, but soon goes?

Since I first experienced it, the noise has not returned. I do an oil change with Magnatec and a flush with Wynns every 6 months (I have a change due now in fact). I have noticed that the oil stays cleaner longer, much longer, than when it did when I first got the car. Its not an instant fix, I would think two or three times using the flush you will see and hear a difference. I have had no issue what so ever in using it. One thing I did notice however was when I changed from Magnated to Edge. Edge seemed to get dirty quicker and I had to top up the level between changes. Went back to Magnatec and there were no problems so stuck with Magnatec since - offers can be had through ASDA now and then for around £20 per tub.

One point I would make though - if you are considering an engine flush then make sure the oil filter housing cap can easily come off and also the oil plug can easily come off. You don't want to add the flush and then find out you cant drain it due to one of the housing nuts or caps being seized. I think the flush is paraffin based, it smells like it a bit. I will carry on using it just because I have the confidence after a few years that its ok for mine. I do think it makes a difference. Also, when changing the oil I do run some new oil through to flush the old oil out before securing the drain plug and finally filling it as I think it takes a bit of anything sitting in the sump out. I guess its just having the confidence in using it for the first time...

[Verbout]

I think if you're curious about it, why not give it a go.

[Linas.P]

17 hours ago, is200 Newbie said:

Since then I have used Wynns flush at every oil change on the Lexus. The rattle you have noticed I had experienced a long time ago when I first got the IS250. After a few oil changes and engine flushes I can only presume that the noise disappeared due to this fact as I was not doing any other maintenance to resolve the noise. The noise, if its the same, sounds like a machine gun for a second or so, but soon goes?

Indeed it is when I accelerate and and gearbox shifts down there is like 1-2 rattle from the engine... seems like it doesn't like changing RPM. I thought that is chain at first, but it was inspected several times and it is fine.

That is reassuring. Thanks for responses. Indeed I wanted to try it, as it matches my issues and other things.. Like having oil cleaner for longer.. just nice to have. Obviously, I was slightly worried about side effects especially after first time.

In terms of oil filter cap - I will go to local garage so they should be ok. But if somebody wants to do the change themselves this is important point.

[is200 Newbie]

Sounds like you have a bad "rattle" mine only happened on start up and only on a few occasions before the flush took effect - never when the car was running.

IS it definitely a machine gun sounding rattle? I have also experienced a what can be best described as a "shiver" when the car was running - used some BG40 and I have not experienced that since either but there was no noise associated to this. Its very unlikely to be an issue with the chain if the noise is as above. The chain can stretch but not to the point that it will create any sound like that experienced.

when doing your flush I always run the car at 2k revs for 20 minutes with the flush in / drain / put some new oil in and let that drain until clear / tighten all the plugs up, new filter etc and then do the new oil fill.

[Linas.P]

So yesterday I finally flushed my engine, yet at the same time I partially ruined the results with "wrong" oil, so now if my engine is going to blow apart... I won't be able to tell whenever that was flush or 0w40 engine oil (well done me !). Anyway that was experiment which I will see how it goes  - you can find more info here :

In terms of initial effect - the oil was extremely dirty (not as if it was clean otherwise), mechanic in the garage said "oh you haven't change oil for a while". So it was definitely cleaning something, the oil was changed 5743 miles ago, but looked literately like 20k+

[is200 Newbie]

Just done my oil / filters and slide pins today - Everything ok. Black Friday prices on a Saturday !! £58 for the oil and filters.which cant be bad.

If your oils black its saturated with dirt / contaminants etc and not working as it should - stick with the flush for the next few oil changes and you will definitely see a difference in the colour of the oil when its changed - may take a few but you will definitely see a difference.

How often do you change it? I change mine every 6 months or so (8 months this time round) and with a flush every change, the oil is never black now when I change it - its dark be not black. It definitely quietens the engine down some after a change. You may find once the oil is changed that you get a rattle - I have had this on most changes and have put it down to the reservoir filling up after it has been emptied so no real issue.

[Linas.P]

True there was some rattle for first few miles, like literally first 2 traffic lights, but then it stopped. 

I do same as you, 2 changes a year, once by Lexus with annual service, second somewhere with independent garages. 

[is200 Newbie]

The garages wont do the flush as a given as part of an oil change unless you stipulate it and even then I would be dubious as to whether they do it at all - one of the reasons I do the services myself because I know exactly what goes into the car.

If a flush is done by a garage - either a dealer or indie - then you should see it on the invoice and depending on how "scruplious" they are there should be a labour charge of around 20 minutes indicated which is the time it takes to cycle the flush properly through the engine before dropping the oil and doing the change. Granted, the flush is put in the engine and then the engine is run to around 2k revs and left for 20 minutes so there's no real labour involved in that but how can you prove it has actually been done as there are no initial indications that it has unitl a year or so down the line when you are still experiencing problems.?

 

[Linas.P]

Well that is why I put the flush myself while waiting for indie to finish the other car, as it happened it was exactly 22 minutes before I got inside for oil change. So all they done was, changing the filter, draining the oil and refilling the oil I have provided, so 100% sure what they did. Obviously if that woudl be Lexus dealer.. they is no way to see what they do or don't inside.