engine flush

A&Q about 350Z

I put some engine flush in my car last week and I have been driving arouund with it in the engine for a week hoping to clean the engine really well, It is a 2000 Van. Am I doing a smart thing? Could this damage my engine? I have a 2005 Kia Sprectra and I plan on doing the same thing to it. Will it help or make no difference

Put correct spec oil in asap.

If you need to clean



When you use an engine flush, you're not supposed to drive the car at all. The car is meant to be idled for 15 minutes and then the oil changed, NOT meant to be driven.

order a new block, heads, crank, conrods, pistons and rings..

Are you serious about ordering a new block, head, pistons etc??? Or are you joking?

depends how much damage is done.

if you've run it and it's causes a lot of wear then you'll need to replace the cam plain bearings in the head (maybe not the whole head) if the cams are worn they won't sit properly and will be worn. the valve train may be worn and might need to be replaced.

the pistons would probably be ok, but if the oil's all wrong they may be damaged from lack of oil cooling. the rings could be very worn, same for the cylinder liners/sleeves.

the crank could be badly worn where it's against the bearings, and if the bearings on the bottom end are worn through the block will need to be replaced. the big and little ends of the conrods (and the gudgeon pins too) could be badly worn, warranting replacement.

you need to test it. that's all a worse-case scenario. do tests (ie compression tests) to see if the bores or parts of the valvetrain are damaged.

OKay, I will do that. So you are saying it is possibe that damage to perfectly good engine could be caused by adding a flush additive and driving the vehicle? Can you explai why? The oil is still in there, I just do not understand and would like to understand why this could have damaged my engine

Engine flush is basically diesel fuel. It does several things:
  1. Drastically reduces the oil's viscosity to the point where it can't maintain oil pressure. This means metal to metal contact on all internal engine surfaces. Instant destruction of most internal parts will happen VERY quickly.
  2. Dislodges all kinds of junk which clogs the filter forcing it into bypass mode. All of the junk in your engine is now circulating unfiltered with the oil/flush
What you have done is in effect switched to olive oil in your engine along with a cup of sand. That's an exaggeration, but its not good.

If your oil pump was up to the task and not too much gunk was dislodged, you have a prayer of not needing a replacement engine. Otherwise its toast. The engine flush is designed to be operated for a minimum of time strictly at idle. What that does is provides enough time to get junk dissolved and into the filter without sending it into bypass, and at idle there is very little pressure on the bearings and internal parts, so the thinned oil isn't allowing damage.

.... unless you're talking about a coolant system flush. That's a whole different animal, but the instructions on the side of the engine flush say very emphatically, idle it for 15 minutes and DON'T DRIVE IT.

it thins the oil. in the same way white spirit thins paint.

oil needs to be of a certain thickness in order to do its job properly, this is based on engine stresses, engine speeds etc..

if the oil is too thin they it's not as good a lubricant as the engine need.

think of it like this, an engine needs really thick heavy oil to make sure all the parts are properly lubricated. now if you use a light thin oil it won't stay on those parts are easily, on rotating parts it might be "thrown" off and won't do it's job properly.

it depends.

What flush and what oil and oil capacity?

A flush could be just light 20wt oil with solvent and aw additives in a 425ml can.

5W20 oil is often used as recommende spec, metal to metal contct is prevented by aw additives ZDDP moly etc or if using a synth polar esters will be in the oil.

A toasted engine may be OTT, maybe worth a UOA and filter inspection to check for damage.

What were the instructions provided with the flush product and did you follow them to the letter? If you did why were there no mention of that in your post? If not, again, why no mention of that as well? Were you trying to fix a problem you had with your vehicle by using the engine flush?

If you could provide a little more detail regarding specifics that led up to using the product, and how you administered it to the vehicle it would help others here provide you with more meaningful suggestions. Given the limited info thus far, I would agree with ALL the other posts in that it is very likely that severe, moderate or even no damage has been done to your engine.
Copyright ? 2006 - 2010 www.cargather.com