Near stall in heavy rain

[GEN 3 SHO FAN]

We had a lot of rain one night this weekend and I was forced to go to shopping center for an urgent need.

I rarely saw as rain as this time. At some places on highway, I rolled on 2 inches of water at 50 mph.

Some minutes later on a red light, the rpm goes very low reaching 200-300 rpms and menacing of stalling what I didn't really want this in the middle of the road, at night and moreover in heavy rain... I put the floorshifter into "P" and the rpm gone to 700-800.

Since I bought the car, it never see as much water. I'm wondering if it can be an electric trouble or the engine just "eat" to much water into the intake ?

As the car seems normal in the next days, I judge then it's not a emergency troubleshot but thanks for the info.

 

[stephen newberg]

Do you have some form of porterized intake?

pax, smn

 

[GEN 3 SHO FAN]

I retreived the saxocone, I put the Gen 4 air box and I porterized the surge tank but not a lot.

Why ?

 

[stephen newberg]

Just curious. Sometimes some water can work its way into the inner wheel well when it is very, very wet out, and that might go from there into your intake, causing the problem. That is just a guess, though.

pax, smn

 

[stephen newberg]

Of course, look at it the positive way. You do not have a Tesla Model 3 where the entire bumper just falls off when it rains hard.

pax, smn

 

[GEN 3 SHO FAN]

Hope to have a Tesla someday but listening to the critics, it will not be a 3... Some Porsche are interesting too.

I forgot to mention that I have no power loss when the light turned green. Maybe the old IAC valve didn't like to drink some water...

Same thing for some people I know...

 

[stephen newberg]

I drove an S just to try it. Fun with the 'ludicrous' button, but it really does not handle all that well. I personally would avoid getting a Tesla, though I like the idea of electric cars. Tesla still loses thousands of dollars on every car it sells, and I have doubts about the long term viability of the firm, which brings into question spare parts if you plan to keep it for any length of time. Most of the car firms are working on various forms of electric cars these days, and if you want one, I would suggest waiting for it from a company that is more likely to still be around 10 years later, assuming, of course, that you intend to keep the car long term.

pax, smn

PS: to get the both of both worlds, I think that Porsche is planning to have what will basically be an electric 911 out in a few years. It could be the one to go for.

 

[98SF19]

The SAI pulls from down low.

 

[Tim Brand]

Don't really no to much on the gen 3 but it's possible that you have a small crack in one of the coil packs. I had a similar situation on my gen 1 even time it rained it would want to die or barley stay running at times replaced the coil pack which on the gen 1 and 2 is just a block not sure if 3rd Gen has separate coil packs for each cylinder or not. Worth a look if it happens again when it rains out.

 

[luigisho]

not sure if 3rd Gen has separate coil packs for each cylinder or not.

Individual coil on plug on GenIII

 

[98SF19]

Not sure exactly how EGR factors in, but if water gets up into SAI, it would either get into EGR lines or out through exhaust, where it would wet the cat substrate and play havoc with O2 sensors.

 

[GEN 3 SHO FAN]

Thanks guys, good comments !

SAI pump is takes his air down below in fact but it put air into the exhaust manifolds, not in the intake... (Which will not disturb rpm as I know.) My O2 sensors are all unpluged right now because I contamined them some years ago. (News are on the way.)

But a crack on one of my old 4 originals front coils can be the culprit... I will check at them.

 

[99sho-time]

it's kinda weird we havn't had much rain but its been a really humid rainy 2 days and mines acting more stally'ish i don't know why. new coils to

 

[Tim Brand]

Are your plug wires new?

 

[GEN 3 SHO FAN]

(We don't have plug wires on the V8, but thanks.) With four old coils on front with possibles craks, I found maybe an utility to the vanity cover in protecting coil from water (which is actually retreived).

99sho-time : What do you have as intake settup ? A cone filter in the fender ?

I'm wondering if the IAC valve doesn't like water. I still have the air box with a tube going in the upper part of the fender. But with all the water this night, I think some was able to reach the tube and the paper filter in the box. If this filter is going wet, it will probably permit a lot less air to pass too. (?)

 

[99sho-time]

I have a k&n cone filter thats boxed in well with a dryer duct ramming air from down below I usually run the hood adjustment screws high as possible and no hood seal( when there no rain) . But I doubt its water getting into the intake . no amount of negligible water will make it to the cats its just to hot. it would have to be a ton of water.

 

[luigisho]

It's been a long time since I had my GenIII but we do get torrential rain over here and I think I remember maybe having a little issue with electric/ignition in driving in deeper water and thought it was associated with the alternator sitting so low. Maybe

 

[99sho-time]

It's been a long time since I had my GenIII but we do get torrential rain over here and I think I remember maybe having a little issue with electric/ignition in driving in deeper water and thought it was associated with the alternator sitting so low. Maybe

that's actually a good point i didnt think of that . damn thing sits very low.

I remember one time I cleaned my alternator out with electronica parts cleaner i just drenched and watched a bunch of garbage wash out of it

 

[GEN 3 SHO FAN]

Good point effectively but I was thinking if Alt going wrong it will cause electrical troubles/gremlins not a power loss on idle. Who knows what a bad ground can makes though...

I don't have to roll in heavy rain since but I unbolted my front coils and they have severe cracks on 2 of them (I kept my old motorcraft for the front bank as they are easy to change). I replaced them by good old motorcraft and the idle is better too (enough to stress me a little on red lights as the motor runs very smooth).

Thanks all for the advices.

 

[GEN 3 SHO FAN]

I always thought that cracks will appears on the the top of the coils but after a verification, I realize they appear on the side of the coils... My first inspection of my original Motorcraft coils wasn't right. I put a photo here for future owners.


Before, this motor runs smoother than a 4 cylinder 2011 Sonata.
Now, it's just a swiss clock.

Edit : I forgot to mention that I have to take the car during heavy rain (but not as the last one) and the imminent stall effect on idle not reappear this time.