Engine cuts off/bogs over 4000 rpm, overheating?
 

I first saw this problem last year in July.

Did a trip from Montreal to New Jersey and about 6 hours into the drive, the car would drop in RPM when idling (this was at a gas station). Eventually the car decided to start bogging over 4000 rpm, which lead to bogging in all gears (downshifting) and then stuttering to a shut off. We waited for about 20 minutes, added a bit of water to the coolant, and off we went again. Mind you it was nearly 40 degrees Celsius out the whole way.

Second time I saw this problem was last month.

Did a trip from Montreal to Ocean City, Maryland and about 11 hours into the trip, the car decided to start acting up again by bogging over 4000 rpm while going through a construction zone on the highway. If I were to try to go WOT in 1st gear, the engine would literally cut off at about 4100 rpm (car didn't stall though). Eventually after taking at exit off the highway, it decided to cut off as I accelerated out of a turn and bogged to a shut off while downshifting. Weather was around 6-8 degrees Celsius coming out of Montreal leading up to about 25 degrees Celsius near Ocean City.

Third time I saw this problem was the next day.

Was driving around Ocean City up an down the strip (cause that's what you do at H2O) and eventually it started bogging and cut out again, same symptoms as the other times. Stopped the car and checked the coolant and noticed I was missing quite a bit. It probably went out the overflow, which thank God, I extended to underneath the car when changing my power steering harness.

Fourth time I saw this problem was TODAY.

Was doing a photoshoot of my car, which involved quite a bit of idling and eventually just driving down the road it started bogging. I didn't let it stall out though. I pulled over and shut the car off myself and opened the hood to let it cool. Weather was a constant 11 degrees Celsius today.

Anyways I need ideas of what to check. I think it's the engine overheating but what do I know.

Last year after the New Jersey trip, I got an engine compression test and everything came back perfect. Ialso tested the coolant system pressure then and that was fine as well.

I changed my radiator cap last night with a Cusco 1.3 Bar cap just in case the OEM cap wasn't holding pressure anymore. This should technically count out the coolant system as being a problem.

I'm running a K&N Typhoon V2 intake, which I will probably put back to stock cause I'm pretty sure that's causing the overheating and bogging.

The only other engine mod I have is a Race Roots Single Exit Exhaust. I also have a GT Spec aluminum undertray (with the fins). The rest of the mods are mainly esthetic or suspension.

Will get an oil change and flush the coolant for 50/50 Prestone this week.

Anything else I should check? Fuel pump maybe? Is there also a way to check if my water temp needle is functioning, because it never moves off the middle mark during these symptoms/episodes.

ANY HELP IS APPRECIATED!

THANKS!

If the cat is not burning up from being clogged, second thought is fuel pump. no more ideas with out year and miles. If the gas in the tank was low, that points at fuel pump, but again, need more data.

2004 GT model with 80,000 kms (50,000 miles) on original motor.

The first 3 times, there was always fuel in the car. Today my fuel light was on.

There is no burning smell or any other odour coming from the car today.

While in Ocean City, there seemed to be the smell of burnt coolant, but no signs of it since the overflow shoots under my car while rolling. There were no puddles of coolant when parked. The coolant smell could have also been someone else's car.

How can I test the fuel pump?

When is the last time you replace your coil, wire, and plug?

2 seasons ago in 2010 (I store the care in Winter). OEM coils, Moroso wires, and NGK sparks.

Did maybe 20,000-24,000 kilometers (12,500-15,000 miles) since then.

So are you overheating or losing coolant or not?

I checked the coolant when it happened today and it all seems to be there. I'm going to flush it and replace it with 50/50 Prestone anyways.

I don't know if I'm overheating because the needle on the dash doesn't move.

The factory needle won't move until 240F, which is too late, damage can occur before that. Do you have a COBB or other device that can pull OBDII data?

My mechanic has a Snap-On OBDII reader? Crazy touch screen one... I have a friend with an AccessPort as well that I'm going to see this weekend for a compression test.

Anything in particular I should check?

P.S. Never did a CEL show up during one of these episodes, except the first time because we disconnected the coolant sensor and reconnected it with the key in the ignition.

Just verify your coolant temps, if you are losing coolant then you have an issue somewhere.

As far as I know I did lose coolant during my trip to Ocean City but it most likely went out the overflow.

I'll check the system pressure again when I flush the system.

Well if it is over pressurizing then there is a problem. Have you checked to insure your coolant fans are working?

Overheat would not cut off your engine above 4k rpm.
It will just kill your engine once it's overheat, doesn't matter what rpm u are at.
And you're in for a new motor.

Replace your plugs or coils, sounds about time.

Fyi, my first set of plugs last 3 years+, second set of plugs last only 18 month.

The fans do turn on, but I only know for sure when I shut off the car and they're still running.

I'll inspect the plug wires with my friend. The sparks and coils should be fine though?

New motor is not an option for me, 2004 year model, no more warranty :icon_tdow

Overheating could cause bogging issues. If he has a faulty coolant seal then coolant can enter the combustion cycle under pressure and cause misfires and bogging issues. That is what happened to my last engine. he said he had his coolant system pressure tested but I would do it again to be sure and possible have the oil tested for contamination.

Same thing happened to me when my plugs went bad.
If coolant enters the motor, you'll see white smoke coming out from exhaust.
Just my though on the issue.

OP, use your best judgement.

I never had any white smoke, only random misfires and bogging at high RPM and the occasional rough idle on cold start up. It was a very tough issue to diagnose and was only confirmed thru an oil analysis and then a tear down.

Just to clarify when I mean bogging, imagine accelerating hard (or even normally) to above 4000rpm but then as you try to accelerate more, the revs drop and jump, drop and jump but don't really go anywhere. Obviously I never pressed the pedal harder to find out what would happen lol

The times when the car wants to stall, accelerating does nothing. The revs just drop slowly (like a downshift) until the car cuts out.

Just to be sure, how many PSI or BAR should the coolant system pressure be at?