Engine cuts out/no pressure in rain [Archive] - GrandAmGT.com Forum


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06-17-2010, 01:40 PM
OOK, so, it seems that when my engine gets wet or it rains and i drive through heavy rain that my engine will all of the sudden lose pressure or act like it won't go anywhere...I will be pressing on the gas to take off, but it will make a loud sputtering noise and barely accelerate, almost as it no air is escaping out of the exhaust, AND the car only accelerates at about 40% of normal, its really really strange.....somebody told me that it may be the cat converter? would it cause this if water gets into it from underspray at a touchless car wash or from rain on the road splashing up underneath? CONFUSED, thanks for the help ahead of time!

06-17-2010, 06:31 PM
Do you have a stock air intake? Maybe your mass airflow sensor is getting wet.

06-18-2010, 06:27 AM
no i have a short CAI...where is the MAF? and how can i protect it? thanks!

06-18-2010, 07:37 AM
Short CAI - you mean a warm AI?
The MAF is the first electrical piece after the intake filter - see if there is any rips in the couplers your using.

06-18-2010, 08:05 AM
Yeah Im not exactly sure what warm AI means...my large cone filter is up in the engine bay between the battery and driver side strut tower...is there a picture of the MAF? and which part of it are people saying needs to be cleaned? sorry for being a dummy, i know exactly what we are talking about just want to make sure!

06-18-2010, 08:07 AM
and should i switch back to the longer intake tubes and put the filter back down behind the fog light? is it better? because i know the filter can get rain water on it and more debris when its the conventional CAI setup (long)

06-18-2010, 08:24 AM
Ya that is a WAI - Cold air is the longer one that goes into the fender well.

Ebay link (http://cgi.ebay.com/ebaymotors/99-04-Grand-Am-Alero-Mass-Air-Flow-Sensor-MAF-_W0QQcmdZViewItemQQhashZitem5ad9f36a54QQitemZ39020 3664980QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccesso ries) Will give you an idea on what it looks like.

06-18-2010, 09:05 AM
ok so i have a war AI...but, what should i do about the MAF sensor? how do i clean it/check it/protect it from water? ALSO, could it be Cat Converter getting wet in rain and making the car cut out?

06-18-2010, 09:47 AM
See if the filter is wet - anything in that area really -
Cat getting wet would not shut the car off -

06-18-2010, 11:52 AM
the car doesnt always shut off...just when it rains the engine will bog down and almost lose all pressure. Then, when i take off, its slowly takes off like there is no pressure and the entire engine sound is muffled and the car shakes....its hard to explain, but i know its not the filter getting wet

06-18-2010, 11:56 AM
Maybe you have a short when it gets wet?
Something is making the car do that - there are no service lights when it starts doing it?

Miss fire would cause the car to shake but prob not your problem - Next time it rains go outside and just start the car - see if it acts funny with out going any where just sit and rev the engine. Take it around the block at an idle - see if anything changes when you get back to race the engine. take a look in the engine bay see if anything is wet.

Are all your plastics in place around the fender wells?

06-18-2010, 12:40 PM
no the check engine light has always been on, but thats because i rebuilt this car and it shows no codes....i have done what you said...its fine when it is just sitting there not getting water up into the engine...i will check fender walls but im positive they are connected fine

06-18-2010, 12:41 PM
it also does this after i go to a car wash that has under spray when you pull in

06-18-2010, 12:47 PM
Why is the check engine light on all the time after the rebuild?

06-18-2010, 01:08 PM
I bought the car wrecked, and rebuilt it, and 2 mechanics have told me that I have a small air leak somewhere in the gas tank (up towards the neck i believe) where no gas spills out but it makes the check engine light come on...im not sure how to make it go away, many guys have reset it for me but it still comes on after awhile....

06-18-2010, 01:33 PM
Ya I would replace that - as gas evaporates.. and your losing $$ in to the air.

Well something is getting wet in the engine bay, causing this all to happen, Maybe its the downstream o2 sensor(?) But that gets wet all the time.. But if there is a wire somewhere free off it it might...

O2 sensor going on the fritz would make the car shudder and run rough.

Some things you have to figure out on your own, and not being able to see the car or get under and look around - this is going to be a Rough one... I had to figure out where my sunroof was leaking - all the dealer did was dirty the headliner, but I found it!

Maybe take a Hose and spray under the car till it start running rough, or in the engine bay - But not on the Altanator, or any thing electrical

Maybe where that crack/hole is in the fuel system does not like water, and is causing the problem?? Sucking the water vapors into the fuel system and causing the problem. There are usually more then 1 fill line, the main and some breather ones.

06-18-2010, 01:59 PM
What would you replace? the whole gas tank? or lines? im not sure what you meant..but i will do the water test with a hose and see if i can tell when and where the car starts bogging down at...also, i will check for wires loose underneath, it hasnt done this the whole time ive had the car, only for about 3 or 4 months when it gets wet

06-18-2010, 02:50 PM
Na not the whole tank - just the fill piece you said was bad/cracked -

06-18-2010, 03:02 PM
well thats the thing...im not sure where that fill piece is? isnt the tanking and fill neck all one piece? that cant be why the engine sputters in rain so badly