Misfire caused by faulty rad. cap?

[6herald6]

Driving to work the other day my '05 Ranger began to idle rough and engine light flashing. I noticed the coolant reservoir overflowing but the engine was not overheating at all. At the shop I saw that the rad. cap was in bad shape and the #5 plug was foul.

What I don't understand is that I'm told the #5 injector must be replaced, and so the big repair bill is coming because the plenum needs to be removed to get to the injector.

So, I'm wondering does a faulty rad. really cause a $600.00+ repair bill?

Fred

 

[lil_Blue_Ford]

No, something is out of whack with that. A faulty radiator cap could cause the coolant to overflow. But I question the faulty injector, just because the plug fouled doesn't mean the injector is bad. A bad plug wire or faulty coil can cause that.


Sent from my kite using a trebuchet

 

[adsm08]

The injector is the LAST thing I look at when dealing with a misfire, unless I have a code for the injector circuit.. I usually start with a coil and plug, on a system like yours I would throw in the other 5 plugs and a set of wires too.

If it is the injector the intake does need to come off to get at that one. Sorry, no way around that.

As for the loose rad cap causing the misfire, it didn't. Much as people like to deny the existence of the phenomenon, especially in relation to vehicle break downs, coincidences do exist and do happen. This is one of those times.

 

[cbxer55]

The entire intake doesn't need to come off, just the upper intake. That's a relatively simple procedure.

What I'm wondering, if coolant was gushing out of the overflow, is the head gasket blown? When my sister's S-10 did that, the coolant ended up being polluted with combustion products. Head gasket was blown, allowing combustion pressure into the cooling system, which pressurized the cooling system, causing it to bubble over at the overflow tank.

Faulty injector would not cause this problem. It would cause a misfire, but not coolant gushing out of the reservoir.

Faulty radiator cap would likely just prevent the system from attaining the 15 psi that cooling systems run at, which raises the boiling point of the coolant. If the system doesn't attain that high pressure, the coolant could overheat while the gauge shows everything to be normal, because the boiling point is lowered as the pressure lowers. Also what type of fluid you have in the system pays a part, especially if all you have in there is water (hope not, but people do do that).