When is a Rail Flush Needed? Before a problem starts or after a problem starts?

[rsiwicki]

I am taking my car 95 Q45t @ 137K miles to the Infiniti dealer this Friday to do a whole lot of work. When I was speaking with the head mechanic there and asked him about a rail flush, he said that I did not need a rail flush unless I was having problems and recommended against such a procedure untill I have problems. What do you all think...I want to do preventive maintenance, but I don't know what I should do on this one. The mechanic recommended a throttle body cleaning procedure, but he said that the rail flush should not be done unless it is absolutely necessary. I currently have no problems with gas mileage, idling, or anything of the like. The car runs very smoothe and idles perfectly.

Also he recommended against an engine sludge flush as well since I change my oil every 3,500. Is this true as well that I would not need this done becuase the oil has always been changed? Also does the dealer use a synthetic oil when I ask them to do an oil change? If not, what weight and brand of synthetic should I ask them to use?

As many of you know, I have decided to keep my car and put some serious money into it fixing it up and I want it running the best it can as I want many more years of enjoyable Qing around town.

BTW....the dealer uses a 3M cleaning process for all maintenance issues like this.

[maxnix]

Also does the dealer use a synthetic oil when I ask them to do an oil change? If not, what weight and brand of synthetic should I ask them to use?

That's a question to ask your dealer.

I recommend going to a distributor and getting a case of whatever oil you choose to save the dealer's markup, assuming the oil you choose is a different brand or weight.

Lots of previous threads on oil by Q45tech, Texasoil, and palmerwmd. Reading them should help you decide.

I bet your dealer doesn't offer the Envirolution crankcase flush.

[Q451990]

I am taking my car 95 Q45t @ 137K miles to the Infiniti dealer this Friday to do a whole lot of work. When I was speaking with the head mechanic there and asked him about a rail flush, he said that I did not need a rail flush unless I was having problems and recommended against such a procedure untill I have problems. What do you all think...

Depends on what (you or your advisor) classify as a problem. Is a problem a dead miss on one cylinder or a variance of more than one bracket on a Consult Power Balance Test (6 or 8 rpm?, I don't remember). My guess is that at 137K you're ready for the injector flush. Typically the dealership doesn't look at power balance numbers, only if the screen says "OK" - meaning that the cylinder is contributing something to the overall RPM count.

If you do the injector flush, be sure they loop the rail output and input lines together so you don't send all of the crud out of the rails back to the gas tank, only to feed it back through the fuel pump and filter. Have a new fuel filter installed at the same time.

Heath

[Q45tech]

The BG system plugs the output during the rail flush. THEN You drain the output [return] line into a plastic bottle after the rail flush is done to see the crud you washed free that didn't get forced thru the injector screens.

Usually isn't much since the 50+ psi pulverizes the tiny varnish particles, that made it thru the fuel filter.

I always start low 34 psi and work my way up in steps, 40,44, 50 psi since it takes 15 minutes for the 11 ounces to burn at idle.

If I'm using my secret sauce...........a splash of this and that added to BG Fuel Injection Cleaner [11 oz], I might vary the idle speed up to 1200 rpm while maintaining the 50 psi.

The octane of the solvents and quasi fuel is very low so it will knock BADLY if you try to use tooooooooooo high an rpm.

[rsiwicki]

thanks for your responses and I have read through the last years archive of previous posts....this is what I have found and please correct me if I am wrong.

Engine sludge flush is probably not needed becuase I changed the oil at least every 4,000 and more like every 3,500. Also it appears that the engine flush systems may not do much good...unless it is this Envirolution system that maxnix posted.

Rail flush - I have not seen where anybody said that this could do any harm to the system by putting undo stress so I am thinking that I will have this done regardless of what the master tech at the local infiniti told me as they are not always correct. As I read in a previous post about knock sensors and my dealer could not identify the problem after three visits and then I took it to another dealer 40 minutes away and they found the problem instantly. I will ask them to do a consult power balance test to see whats going on also.

I wish timing was better for me as I would be driving up to Atlanta to see Denise @ T3 there to have all this done and the piece of mind knowing that my car would be in good hands with all the surgeons working on it giving all the attention it needs. Often I think the dealer mechanics see the old car and pay less attention to it as they probably don't think that the owner really cares that much about the preventive and longevitiy of the car and the customer is more worried about the $$....IMHO. I might have to pay a visit to T3 this summer with my car for a general check over, besides that I have a god child in Atlanta that I need to see.

[DAEDALUS]

Convince yourself (and us) the rail flush is worth it. Get mpg data for at least 3 tanks before and 3 tanks after the flush. I flushed my Q a year ago, and the mileage improved drastically. I did a rail flush on my Dodge today and both me and my gf are certain there is a big difference in the sound of the engine, smoothness and power. I also replaced the O2 sensor though, so any mileage improvement will be a combo of the 2 services. I keep meticulous data on all my vehicles; I will post in maybe 6 weeks to report back on the mileage improvement. Unfortunately, it'll probably be offset by the CA switch to RFG.