Engine flush

[ahing6]

Has anyone ever tried, has experience using an engine flush before an oil change?

I've heard stories over years of risks of messing up rubber seals.

If so does it depend on age of engine/ seals?

I got a 405sri 1998cc couple weeks ago, the car was not given due attention by PO.

I changed auto trans oil twice and added trans additive. It now engages normally without revving to 3K rpm when cold.

Rebuilt power steering rack, right gaiter was shredded, line crack leaking to ram etc.

So now i want tackle engine oil and drop the oil pan and clean out sludge am sure has accumulated.

So what think is best..... forget flush and just drain/drop oil pan?

Roger

[Bean]

I've used Seafoam as an engine flush - I added it to the oil while the engine was hot and I idled it for about 20 minutes before draining.

If you don't have a similar product as Seafoam, then you can also run a litre of ATF added to the engine oil for a week or so prior to the engine oil change.

Dropping the pan and inspecting is always a good idea if its not too hard, but definitely consider a flush or running ATF to dissolve as much as you can from other internal engine oil passages.

For the record - ATF is a very high grade oil with very high detergent qualities, so its a safe "cleaner" to add in moderation. Ideally you want to top off the oil with it, but not more than 1L.

Rabin

[ahing6]

Ok well ATF i have but the Seafoam i will investigate. So can i run it with ATF for a week and Seafoam just before i drain out?

Am also seeing some sort of toffee looking stuff under the oil filler cap but not on dip stick. What's that about?

[Bean]

Yes - ATF for a week is fine. If you can run Seafoam as well before draining that would be great - but not necessary.

Toffee coloured goop is moisture in the oil, usually condensation if the car is only used on short trips and not fully reaching operating temp. Worse case scenario is that it could the the first signs of the head gasket starting to leak.

If it shows up on the dip stick then it is the HG and you should repair quickly and not drive it.

Rabin

[ahing6]

Ok will do the ATF for sure, as i have never heard or seen Seafoam product down here.

yes i do some short trips, so yeah moisture.

Thanks again.

[V-M]

I have used diesel 0.4-0.5L in ^4L oil amount. Procedure is at add that diesel and run engine ^15min in 1500-2000rev and then change oil and filter (basically same instructions as those official ones). I have used this procedure last 6 years in all engines I have. Earlier I did buy these official engine flush things. But when I found out at thats 99% of same stuff, I started use normal engine diesel oil. Here in Finland is also 2 variations of it, taxed one and no taxation. I have used that non taxated version of cause cause its cheaper and same stuff as taxated one (only red colorizing agent used). Surely every one uses this at own responsibility.

V-M

P.M I have noted at some flush manufacturers are giving wrong instructions when using those. Never run engine in idle revs after agent is put on engine.

[ahing6]

I have used diesel 0.4-0.5L in ^4L oil amount. Procedure is at add that diesel and run engine ^15min in 1500-2000rev and then change oil and filter (basically same instructions as those official ones). I have used this procedure last 6 years in all engines I have. Earlier I did buy these official engine flush things. But when I found out at thats 99% of same stuff, I started use normal engine diesel oil. Here in Finland is also 2 variations of it, taxed one and no taxation. I have used that non taxated version of cause cause its cheaper and same stuff as taxated one (only red colorizing agent used). Surely every one uses this at own responsibility.

V-M

P.M I have noted at some flush manufacturers are giving wrong instructions when using those. Never run engine in idle revs after agent is put on engine.

Hmm...... well i currently have a litre of ATF in engine to run for about a week.

Maybe i also try .04L of diesel just before i flush ?

Keeping rpm at 1500 - 2000, is that to ensure oil passages don't get clogged with bits of loose debris?

The engine is over 10yrs old '96 model. And the previous owner was not that diligent with car fluids.

So am hearing stories of risky to flush older engines...... is this true?

[Bean]

V-M makes a good point about not idling the engine during the flush as idle will have the lowest oil pressure, and it'll be even lower with the flush. Key is to ensure no load as well, so I would say a constant 2000 RPM or so would be good.

If the oil is that bad you should swap the oil filter now so that the current one doesn't pack up. Change it again when you do the oil change, and don't used Fram filters.

I also disagree with people that say flushing is bad, or to never change automatic transmission oil. If done right it won't cause any issues, but if something does go wrong it's due to the poor maintenance and not the fluid flush.

Rabin

[V-M]

Yeah... I do only 4000-6000km with oil changes and allways change filter also in all my cars. filter is cheap part and expands engine life. why not fram filters? never had any probs with fram.

Flush is dam good way to maintenance engine, its also bit dangerous cause it can damage if not done properly. Automatic oil need to change in every 20000-30000km or in 3-4years (I use 40000-45000km and 5years on my saabs).

V-M

[andrethx]

why not fram filters? never had any probs with fram.

you're in europe, so the fram filters you get are not the same ones we get in north america, i'd guess. lots of people here have had problems with fram filters failing catastrophically (google it, you'll see what i mean). fram was once a well-respected brand of oil filter, most people trace the slide in quality to when production moved from the US to mexico. lots of good stuff is made in mexico, so no doubt fram used the move in production as an opportunity to cut corners on the quality as well.

andré

[Bean]

What Andre posted... Specifically poor construction, poor filtration media, and non-existing/non-functioning drain back valves.

I only use Purflux, Mahle, Bosch, or the best Napa Gold or Wix filters.

Rabin

[ahing6]

Just an update on things done past week end.

Added 400ml of diesel to engine and ran it at 1600 rpm for about 13min. (thanks advice V-M)

Drained out but did not drop oil pan.

New Champion F118 filter. 306, 406 & 405sri use same.

Fresh 20w 50 full synthetic Amsoil.

Oil is still looking clean after wk end driving. Usually instantly black without flushing.

Installed new water pump (bad leak)

New timing belt & serpintine belt.

Also added stop leak to radiator about 2 weeks ago and no more toffee in oil cap, but still losing some water......hmmmm

Now when i bought the car the idle was between 1000 - 1200 rpm and started great from cold.

But after a trip and over 10 min passed it will take at least 5sec cranking to fire up.

And wham 1500 - 2300 rpm !! then slowly drop to 1000 - 1200 rpm.

So every one said bad stepper motor..... change it, but i was not yet convinced to do so.

The A/C needs R134 & service, but i could not turn off compressor and just use the blower because of bad A/C switch on facia panel.

Disconnected compressor wire pins.

Then while fiddling with A/C switch while engine at idle, i held it down wit finger and........yeeess 900rpm !!!

Seems switch stuck on position and fooled ECU to step up idle......

So i pulled out fuse (5a) for blower, recycle & A/C compressor.......end of iratic idle, long cranking starts when hot & high rpms.

Easier to drive now and starts just a turn of key hot or cold,goes up maybe 1500 rpm and quickly drop to 900 +- 50rpm.

Wow ....all that from faulty A/C switch.....

Roger.

[V-M]

Just one note if usage temp is not going under -5C use only mineral oils on old cars. Just change it often and with filter and engine will work longer and more efficient.

V-M

[Bean]

I'm a proponent of synthetic oil all year round as not only is it better in extreme cold, but also in extreme heat.

Only issue I've ever found is that seals might leak more, but its never been an issue for me as I usually reseal motors if that's the case.

An example of why I like synthetic: Volvo's are known to need periodic PCV maintenance, so as a preventative measure I did the complete service at 200K. I was expecting some carbon build up, but what I found was a spotless PCV system. None of the ports had any carbon build up what so ever... I had all the parts so I replaced it all anyway - but it was yet another aspect on why I like running my motors on AMSOIL.

Rabin