Hi all, new Prius v owner

Hi all,

New problem. After sitting for quite a while ( COVID, you know ), I started the car and got the dreaded engine knocking. The first time it threw misfire codes ( P0300, P0302, P0303, P0304 ). Seems to be continuing to do it whenever I start it.....but no new codes after clearing them.

After poking around a bit, I saw it could potentially be :

• A low 12V battery.
  • Unlikely,...the 12V battery voltage looks fine.

• Bad ignition coils.
  • Could be...However, seems odd that I got misfires on multiple coils?

• Bad plugs.
  • Could be....However, same as #2 above...seems odd that I got misfires on multiple coils?

Any ideas on what I should do to tackle this? I threw some Techron in and I'm running the engine to see what that does ( not expecting much ). I may try replacing the plugs/coils first...because it looks pretty straightforward ( well, except for having to remove the wipers and cowling in the cold, etc... ).

@Mendel Leisk, @Raytheeagle ...I added you in case you have any further ideas.

Thanks!

 

Coolant levels are just dandy....so doesn't appear to be a leaking head gasket ( thank god ).

I removed the MAF sensor and inspected it...looks like it is in mint condition.

I did originally rule out an EGR blockage issue because I 'recently' replaced the EGR, cleaned the throttle body, etc...( see previous posts ). However, I need to check it just to make sure. Come to think of it,...'recently' was a couple years ago now....but mileage wise, not all that much. I would certainly hope the EGR wouldn't be fouled again so soon, but who knows! Also, I never did get around to installing a catch can...so maybe that plays into it and is another reason why I want to inspect the EGR, etc...

Seems like the point of least resistance is to inspect/change the plugs and possibly swap out the ignition coils...However, I also replaced the plugs a couple years ago when I replaced the EGR, etc...so the plugs 'should' be fine.

Just really odd that the car has had absolutely no problems until it was sitting around for an extended period of time. Also note that I did have it connected to a battery minder...so the 12V doesn't appear to be the problem ( and was the first thing I checked ). Bummer this has to happen during a Minnesota winter....haha.

 

Haha yeah..I do need to take it our more. However, I like driving my wife's Elantra GT lately...it is a fun little hatchback!

I'm hoping shoving a buttload of Techron thru the system might help...We'll see.

 

Well the more I read about misfires, the more I think I need to rule out the dreaded head gasket issue. Certainly might not be the head gasket but best to rule out the worst case scenario first I guess while I'm trying other things.

These 'combustion leak testers' are pretty interesting. I ordered one to try :

www.amazon.com/gp/product/B000NPDL76/

Also might try the 'endoscope down the plug hole' trick to check the top of the cylinders. Ordered one of these endoscopes to play with :

http://www.amazon.com/gp/product/B07ZH9P8QH

Why? I like toys...and I have some amazon gift cards burning a hole in my pocket.

I'll report my findings back. It may be a while...I also need to find a day warm enough to work in the garage...or also invest in a garage heater. Hmm that might not be a bad idea come to think of it!

 

Update on the knocking. Im stumped....but good news....no more knocking....but it just 'started to work'. Even in the bitter cold, etc....See posts above for review.

I'm still going to do some diagnosing when it gets warmer out...but I'll take it at this point. Any theories why the knocking magically stopped? Very odd!

 

Knocking update #2....still no knocking...it seems to have 'went away'. I'm continuing to monitor coolant levels and such.

I'm wondering if it may have been an intermittent fuel line thing...or something of that nature. The car had been garaged for long periods of time over the winter ( hooked up to a batter minder ). After a recent discussion on another thread about 'old gas' and the theory of possible intermittent condensation, etc... I'm wondering if it might have been something related...

 

Knocking update #3.

The knocking started again...very regularly. I noticed it intermittently...but our daughter started driving 'the v' daily after her accident ( see Hi all, new Prius C owner | PriusChat ). Unfortunately, she has also noticed the knocking almost daily. I just dropped her off at the airport and drove it for the first time in a couple weeks. Wow...a lot of knocking...enough to throw misfire codes! I was able to drive it home though.

When I got home I checked the coolant level and sure enough...the coolant level was lower than it had been. I then used my combustion leak test kit and sure enough...the fluid turned from dark blue to yellow :




So TWO telltale signs of head gasket failure now...

Luckily, I 'know a guy' and I'm getting a quote...but I know it ain't gonna be cheap! Geez...can the car issues stop now please?


Tagging @Mendel Leisk and @Raytheeagle for the heck of it.

 

I did some research on specialist shops in the MN area and ended up calling carspecmn.com. Looks like a great shop...and has been mentioned around here on occasion. Quoted me $2900 for the head gasket work...which also includes a new EGR and EGR cooler. Seems in the ballpark for what I was expecting. I'm close to going with them to do the work. I'd rather not get rid of the car as I've done a ton of work myself on it ( read the rest of this thread to see! haha ).

 

Good idea...but I already have a spare EGR cooler. But yeah...I suppose I could sell it.

BTW - I already did an EGR swap not too long ago ( edit - I guess it was in 2018 ) when we purchased the vehicle with 128K on it. ( it has around 168K on it now ) :

Hi all, new Prius v owner | Page 3 | PriusChat

The EGR cooler was NOT completely clogged at the time...but was somewhat clogged. The EGR swap sure didn't seem to help the head gasket situation!