2.5 V6 Cougar tuning.

[supersmoothpunk]

I`ve bought a V6 cougar a couple of months ago with 101000 miles on it. It runs and drives good.
The only thing I have found is at lower revs it really feels like it is missing and it lurches a bit. I pulled a plug out and it looks like its running a bit lean. There were a few perished pipes that I taped up and some loose jubilee clips that I tightened but its still doing it. I plan on changing the plugs as they are probably the originals.
Also does anyone know any tune up tricks for this engine.

[Deleted]

you need to get the engine running as it should before starting to get any more power out of it,ie replacing pipes not taping them up. check stuff like the IMRC secondary butterflies are opening/closing as these are probably the main cause of running issues on these
Don't waste money on anything other than Ford Motorcraft plugs,engine is sensitive to any other brand,even ngk's!
Then it's the usual exhaust,air filter stuff. the Cougar has 3 cats fitted.The pair fitted in the exhaust downpipes can be gutted easy enough by drilling a small access hole then ramming a bar up to smash the cat out
Better flowing manifolds can be got easy enough on ebay but can be a nightmare to fit
Next stage is fitting the induction setup from a Mondeo ST200.bolt on stuff
After that and you are looking at engine swaps for the 3 litre engine/superchargers have been fitted but thats serious money then

[ChasR]

I'd agree with Andy. Neglect a V6 (cooling, maintenance etc.) at your peril. On song they are a lovely thing. Not on song they are a complete and utter nightmare, especially with their lack of space in the engine bay one has to contend with.

Does it idle well or could it be better? IME the Idle Control valves can play up, but an anti-moosing pipe (A pipe going from the inlet to the inlet pipe after the airbox and MAF sensor) can cure a number of low end drivability issues (in addition to curing a moosing sound that can affect many 2.5s).

I would replace any pipes that are dubious, check the ignition system over one time (I must admit that Motorcraft plugs do give consistent results over other brands (at least they have done for me) in addition to lasting a little longer. The IMRC ECU can play up due to the internals taking a battering from engine heat. This can cause the secondary inlet flaps to be fully open (causing low end torque issues), or closed (hurting the top end.

With the mods I did on my 2.5 a good service really livens these things up as does ditching the main cat (last cat in the exhaust system). Even on my 2.5 Auto Mondeo it still had enough torque around town but it was a lovely thing to drive with more of a revvy nature in addition to delivering slightly better fuel economy (22-24MPG around town with not all that much careful driving!). It also sounded a little fruitier too!

Ditching all of the cats and getting tubular manifolds however is the best bang for buck increase IMO. The stock items really are awful on the V6s. The manifolds are not too bad to fit but having patience with the job is almost mandatory.

At the moment I am considering getting a set of tubular exhaust manifolds for the 3.0 Mondeo, but I really should crack on with the retros!

[supersmoothpunk]

Cheers for you replies. The car is in really good order generally the oil looks clean, the coolant looks like new, so does the oil and air filter.

It normally idles ok but occasionally I get throttle hang and the revs will sit very high. I read on the cougar forum that a copper pipe stop with a hole in, in the tube from the EGR would cure it.

I have got that moosing sound sometimes when I first start the car or when its revved hard. Hows does the pipe from the inlet to after the MAF help low end driving? By providing more air that the MAF knows about?

Did you have emission issues when it came to MOT time when the back cat is taken off? I would like it to sound a bit fruitier.

Where are the secondary inlet flaps located?

Thanks for all your info its much appreciated.

[Deleted]

Get yourself over to www.ukcougarforum.com/vb/forum.php
they have answers to pretty much any cougar related issue you can think of

[ChasR]

The moosing sound is cured since the pipe is much longer than the stock item, hence the resonant frequency has been shifted. For me it also cured a misfire just below 2,500rpm. I can only assume that the resonance throws off the ICV.

With the rear cat removed I had no issues come MOT time. I would however if you have any doubts get either decat pipe off ebay (many people sell them secondhand) or get one made, keeping yours as a spare. The strange part to this was that my friend with his ST24 always used to fail his MOT and that was with a Mongoose twin box exhaust system fitted (that sounded lovely, albeit it was not really all that much louder than my otherwise stock Mk3 2.5 (exhausts are pretty much the same on the Mk2 and 3 V6s bar the ST220). His MPG was by no means comparably horrific either.

The secondary flaps are located in the lower part of the inlet manifold (it is in two pieces).

I found the 2.5s a little more 'fun' than my 3.0 although the 3.0 certainly has a little more torque at the bottom. It is a little more boring at the top (the 3.0 is very much a smoother operator of an engine, linear across the entire rev range, bar the ST220 which is a little more lively).