will highway driving clean engine?

[WmWatt]

The carburetted '89 Festiva has been driven short distances all winter and the PCV valve is full of foam, also foam under the valve cover. The soot has been wiped off the spark plug tips. I plan to take the car out on the highway to burn off the foam. This is prior to the required emissions test.

Is there anything else really needed to clean up the engine or willl the high speed driving burn off the winter's deposits?

Thanks.

[FestYboy]

you gotta get the engine up to temp to burn (boil) off the condensed water in your system. get it hot and KEEP it hot for a while.

[denguy]

Disconnect the fan and let it idle a while. Keep an eye on it.

[FestYboy]

^ NO!!! wth!? why would you do that, you want to stablize the temp, not cook the engine.

[denguy]

I said to keep an eye on it.

[Pu241]

I said to keep an eye on it.

Yes, and exactly what would he be looking for specifically to know when he's let things go too far, and now has a warped head?

Take it on the highway for a good long drive, say at least 50 miles round trip, then change the oil.

[TominMO]

I'd add some fuel system cleaner to help the process along too.

[200KGPGTP]

Take it on the highway for a good long drive, say at least 50 miles round trip, then change the oil.

I would do this in reverse order

[Pu241]

I would do this in reverse order

No disrespect intended, but give a reason why.
I might have to agree with you.

I would change the oil after the drive, because if it hasn't reach normal operating temp for some time, the oil is still good. And at full operating temp would likely still be able to keep crud in suspension to be removed when the oil is changed. Basically getting maximum use out of the oil before changing it.

[georgeb]

I don't think sludge will effect an emissions test. If the car is only used for short trips you have to change the oil more often. One highway blast won't do it.

[windy1]

cleaning engine

u,ought to get a can of GUNK engine cleaner. after u warm up engine,put in 1/2 a can or whole can. then follow directions on gunk can. or,take car in to a garage,and have them flush the engine out,on a machine. always change oil,after engine is warm . sea foam,works,like gunk. luck,dude

[ztittle]

To me, foam in the PCV and valve covers means blown head gasket and you're getting coolant in the oil, which will destroy an engine. When oil and coolant mix is makes the oil very foamy/sudsy and runny effectively making it too thin to work properly. With the lack of coolant and contaminated oil an engine will overheat and blow real quick.

I would check the coolant level before heading out next time. If it is good then hopefully this isn't the case but I've seen several cars die from this. (Mostly people not letting their cars warm up in winter causing a blown head gasket..idiots..)

But for general cleaning, I'd use a good ol' can of SeaFoam. 1/3 in oil, 1/3 in tank, 1/3 sucked into vac intake line off Brake Booster. Have a friend rev the engine till it's all sucked up, let it sit 10-15 mins, keep engine up at high revs till smoke clears. Then I'd change the oil shortly after some normal driving.

I brought my wife's 84 Honda back from the grave with a single can of SeaFoam, its great stuff! It would take 45 sec of continuous cranking to fire up and would die if you let off the gas. After 1 can of SF it started right up 1-3 cranks for years till the water pump died and we sold it. It is still driving around today with near 400k on it

Sorry I'm a bit of a wind bag sometimes lol

[getnpsi]

I'm not a fan of a harsh solvent on an engine that is really dirty. a chunk can break free and go into bearing or clog the oil pickup. With a 3.5qt capacity if you decide to do seafoam or gunk in your oil I suggest doing a half dose 2 times. I used 5w-20 in california summertime and she did fine, so going to a 20 in the winter/spring elsewhere will be fine.

Seafoam is good for rings but does little for valves. The top end is where things need to be cleaned and burned off. Replace pcv, check all the lines to make sure they aren't cracked--a vacuum leak can make the car run erratic and actually richer, causing cooler temps and more buildup. Replace thermostat with the higher temperature OEM dual stage, and run some 5w-20 oil.

[Bert]

I loathe those G.D. bi-annual Ontario e-tests. And whatever money you invest ahead of the test does not count towards the designated 'attempted repair/conditional pass' financial allotment either should the car fail. I don't know what that number is these days but it tends to exceed the value of a normal 20 year old car. I've had good luck with an independent emissions test facility that is very near you on Merivale Road across from the Loblaws Superstore. Car dealers and auto repair garages have a vested stake in praying that you fail, don't you know.

Ethanol in the fuel (or even a very temporary dose of Methanol) does not contribute to harmful emissions so I make darn sure to show up with a generous amount of that stuff (there is an 85% ethanol eco-fuel station on Woodward Ave at Clyde) in a partially-filled tank, which is quickly re-filled with ordinary gas after. Change the oil and filter (and perhaps the PCV valve) just before you go for the test. Bring the car in 'hot' (ie even leave it running in the waiting area) because catalytic converters require a high operating temperature to function optimally. Clean the plugs and maybe run some carb cleaner through and drive the car up and down the Queensway (Hwy 417) from Kanata to St Laurent in 4th gear for 1/2 hour to get the carbon deposits out.

One of these days the gov't is going to get smart and exempt all non-OBDII vehicles from testing!

[getnpsi]

@OP: make sure your o2 sensor is working. That right there can cause it to run in limp mode, again causing a rich and cooler burn.

Speaking of limp mode, y'all should check out the recent american Top Gear where they did the three minivans trial in the rocky mountains. There was some trash talking asking about someones "limp mode" and did it involve drinking. Really good episode compared to the others.