Advice on Redex/cleaning an engine

#1
I know redex is largely seen as a snake oil. But from what i am reading, people are trying to use it on relatively new cars or ones that do a lot of long distance driving.

I however im thinking of using it in a van that is largely used a few times a week for short journeys, mainly local deliveries. Its only being driven for 15-30min max a few times a week at the moment. Its a Renault Master that is well over ten years old and a few years ago had a problem with the Exhaust Recycle Valve being so cagged with carbon it blocked it (it has since been cleaned).

So im thinking of something to do to the system to help give it a clean through without having to strip it down. Im not expecting a complete clean out, that requires a mechanic, but more some general cleaning to show i some love. Is redex an idea on this instance, or is there a better product?
 
#2
Redex or similar cleaners do work. My father's volvo failed MOt on exhaust emmisions. Tank full of petrol with a maximum dose of engine cleaner in it later and it passed.

Just make sure you buy the product appropriate to your engine (eg carburettor or injection, diesel or petrol).
 
#3
All fine get i t cleaned, but also be prepared to check the fuel filters and plugs after you've fired it through the engine. remember it's a solvent designed to lossen deposits - those deposits have to go somewhere and can often cause serious problems. After that just use decent fuel - i.e. a BP, SHell Esso type as the detergents in the standard stuff will keep the stuff clean. All though you could scrub all of that and just use their premium Supers, diesels as they have "get clean additives in them"
 
#4
Another tip is use good quality petrol. Most of the mainstream brands have engine cleaning additives added. I am not so sure about the smaller brands or the supermarkets.
 
#5
Doh, PS beat me to it!
 
#6
Fill tank up and throw a whole bottle of Redex in and go for a good long boring drive on a M/way, it does work. Same goes for injector cleaner.
 
#7
Fill tank up and throw a whole bottle of Redex in and go for a good long boring drive on a M/way, it does work. Same goes for injector cleaner.
This works, as good spanking down the motorway for 30 minutes really clears the crap out.
 
G

goatrutar

Guest
#8
We use injector cleaner in all our trucks here. Works well keeping the smoke down and burning off the glaze.
 

jarrod248

LE
Gallery Guru
#9
The diesel version of redex is good but also for your old diesels especially before an emission test. Take them for a run high revs in each gear. Take them on a motorway don't redline but in each gear get almost that high and keep in a lower gear 3rd or at most 4th and give it a run at higher revs but lower speed. Watch what comes out the back. Mile or two should shift some shit.
 
#11
A good thrashing aka a Italian tune up and some good cleaner does work , as does running it on good fuel , supermarket stuff is rubbish . My car runs rough , hesistates when cold and pinks slighty under high load on cheap petrol .
I had it cleaned with Terraclean when i got it and that gave a amazing improvement .
 
#13
When i was a kid my mums cars always used to run like shit so i would take them out for 30 mins and thrash the pants off them , then they went a lot better . I gave that up after hitting some black ice at 60 mph and nearly ditching it !
 
#14
A good thrashing aka a Italian tune up and some good cleaner does work , as does running it on good fuel , supermarket stuff is rubbish . My car runs rough , hesistates when cold and pinks slighty under high load on cheap petrol .
I had it cleaned with Terraclean when i got it and that gave a amazing improvement .
Petrol or diesel, age and mileage?

Considering getting mine Terracleaned and have read nothing but good reviews of it. Something is putting me off though, almost seems to good to be true. Engine is in decent nick anyway, was just considering getting it done before a remap.

For the years old OP, I've always stuck BP in my cars with the odd tank of super/premium, maybe every 4th/5th tank and I've never had any trouble from that side of things. I've also found I get better mpg from any time I've had to put supermarket cack in.
 
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#15
Don't overdo it though. Redex can destroy your catalytic converter and you'll fail the emissions test on the MOT.

On the subject of MOTs try to go to a station that employs MECHANICS, not FITTERS, like Mr Clutch etc;

I bought a second hand car, that had a new cat fitted only a year before according to the documents. I stupidly went to Mr Clutch for service and MOT, it being nearest to me and they told me it failed the emissions test and needed a new cat. I told them that the car had only done 4500 miles since the new cat was fitted, and I didn't believe the cat needed replacing. Mr Clutch's answer is let our FITTERS fit a new cat @ £279.

So I took the car to a MECHANIC. He tested the emissions. 'Yes its a fail but the cat is probably dirty. I'll clean it out' the MECHANIC says. And an hour later I have an MOT certificate and no bill for £279 to replace a cat that only needed cleaning out.

I had used Redex prior to the service and I think it shifted the shit from the engine to the cat, causing the failure.
 
#16
I have restored and rebuilt a few marine Diesels, ( just started work on a 3000 lb cast iron Lister JP3M with 4 & 1/2 " bores )I wouldn't even consider using it, even if it was free. Only because I know what fouls up injector nozzles, and no magic juice from Halfrauds is going to shift that. They need proper sevice and re calibration. If it does remove carbon fouling, then you don't want abrasive dirt in your bores anyway.

Rumour is that its just a very expensive bottle of kerosene.

These are all mechanical injection though. I don't know diddly about cars.
 
#17
Redex etc all work a little bit but won't work miracles , neither do the additives that will "repair" your slipping auto box or leaking power steering.
What it will do if used regularly will stop build up of the deposits and in older mechanical injection engines will provide a bit of lube to replace the sulphur that diesel no longer has as a lubricant.
EGR valves block with a soot / oil/ carbon mix from as the name suggests recirculating exhaust gas , this contains soot particles from the combustion process that then mix with the oil vapour and oil from the crankcase breather that also routes on most vehicles into the induction side of the intake just downstream from the air cleaner , fuel additives will have little affect on this process , short journeys at low engine revs and speed / temperature have much more influence and effect , same happens to DPF's , the answer as many have said is to drive it like you stole it every now and then.
Fuel injectors are a wearing part of the engine and in the case of mechanical systems are getting worn at 80 - 100 K miles but will work for another 100K just with loss of power and fuel consumption .Modern common rail diesels use injectors and systems that can compensate for wear up to a point but still do loose efficiency over time.
Many diesels can pass the MOT emissions easily with the EGR blanked off and the cat or DPF bypassed by means of tubing it so that it appears visually to be present to the tester . If carried out properly with a remap the engine will perform better and do more MPG.
My Landcruiser has the EGR's blanked off and a straight through free flow exhaust and passes the emissions on the fast test every time at about 60% of the limit , it also is about 35 bhp more and a lot more torquey than when it left the factory and for a 4.2 Turbo diesel is good for 30+ mpg .
 
#18
Petrol or diesel, age and mileage?

Considering getting mine Terracleaned and have read nothing but good reviews of it. Something is putting me off though, almost seems to good to be true. Engine is in decent nick anyway, was just considering getting it done before a remap.

For the years old OP, I've always stuck BP in my cars with the odd tank of super/premium, maybe every 4th/5th tank and I've never had any trouble from that side of things. I've also found I get better mpg from any time I've had to put supermarket cack in.
Petrol 70,000 miles , previously not used for very long journeys . The thing was very gutless and felt strangled . I too had my doubts about it but the difference it made was unreal , it felt like different car . It had been run on supermarket rubbish though and the short journeys dont help . I spoke at length to the owner of the garage [ Scotland ash garage] about it and he explained that its something that may become more common due to the new diesels having exhaust particle filters and direct injection meaning cars are great on fuel etc , but run very dirty inside .
He said its recommend as service thing really , like every 10,000 miles or something .
I wont be taking my car back unless i really feel it needs it again [ its only worth £3000 ] .
I would say its worth doing myself , even though you hear all the ' snake oil ' stuff . At the end of the day it works for me and countless others , and i dont fancy spraying water / alcohol mixes into the chambers myself or any other of the doubters advice .
 
#19
One thing. Check your exhaust for any holes/leaks. Especially the down pipe from the manifold. That's an easily curable problem for bad emissions but one often overlooked until the MOT tester points it out to you.
 
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