Exhaust fumes on Startup

Hey y'all,

Okay, this is going to be an interesting post.

A little background on my Prius, I have an 08 that has around 179k miles on it and have never had any major mechanical problem. I have always kept up with routine maintenance. I use Synthetic oil and change it about every 6500 miles.

So, two weeks ago, it was time to change the spark plugs again. Carefully, I took out the old spark plugs and installed the new spark plugs. On the second spark plug wire and spark plug, I noticed a little bit of oil, so I wiped it off with a shop towel, installed the new plug, and kept going.

Interestingly enough, now I have a problem where when I first start my car (and only when I first start it) and I just have the interior fan running (not with the A/C on) I get some serious extreme exhaust fumes through my A/C vents and that wasn't happening before I changed the spark plugs.

Now my first thought was, "Shoot, what the hell did I do to my car?!"

Here's the weird part, once the ICE has warmed up and shut off for regular "ready" mode, I don't smell it ever again even if the ICE activates as I'm driving. Note that at this point, I haven't made any changes to what fan speed or setting the climate is on.

As soon as I turn my car back off, then back on again by pushing the power button, out comes the awful exhaust fumes again.

So, here's where the testing stage comes into play. I have tried everything I can think of. Yesterday, my father helped me take the air box off and we made sure all of the hoses were attached and the recirculation hose didn't have a clamp. We replaced the clamp and resecured all of the hoses in the engine thinking that there might of been a loose hose with the exhaust recirculation.

Unfortunately, none of that made a difference. I did notice some gumption in driving it this morning that wasn't there before, but I still get fumes at startup.

I read also somewhere where there might be a fuel leak. I checked the line, there aren't any cracks and I didn't see any puddling or wetness anywhere in the engine bay. I try my hardest not to overfill my pri.

I am lost for words as to what this could be. Could the manifold come apart? My car was in the shop about 3 months ago due to a lovely bambi that ran out in front of me, but if they didn't fix it right then it should be the shops responsibility to make it right.

The weird part though, is I never noticed it until I changed my spark plugs.

Any insight on this would be great. Thanks y'all!

 

I'll have to take that apart later tonight to check to see if there is any leakage. Good point to that thread, mine weren't that dirty at all, it was like 2 little drops of oil. Not anything that I was concerned with.

I seriously hope there is no crack in my exhaust system. One of my friends told me to check out the flange gasket to see if it might be cracked.

thanks for the insight man!

 

By the way, definitely smells like exhaust and not burning oil. Just wanted to clarify.

 

Hi guys!

Thanks for the wonderful tips. Just to be sure I retightened my plugs this morning with my neighbors torque wrench to 13ft -lb and I'm still getting the same result.

I now know to do that in the future, however, I'm rolling in the same boat. Someone in my family told me to check the flange gasket to see if that might be the issue but at this point I'm starting to research someone in the area that can take a look at it.

I appreciate all of your input! I may need to replace the flange gasket, but I'll get someone to do that for me.

Btw, when I retightened the plugs this morning I saw more oil on the plug. :/

After 180k miles, this is only minor and obviously could be something easy to fix.


Again, thanks guys!!

-Alex

 

Hey everyone, just an update to close out this thread

Here's what ultimately happened with my car:

I was able to get it looked at by both a Toyota Certified Mechanic here in town, and they weren't able to find anything wrong with my car, however, I was still able to smell exhaust fumes at startup and I was getting some really horrible MPGs. I was filling up 10 gallons to 300 miles! I couldn't believe it. I spent a lot of exhausted research trying to fix my car. I replaced the PCV Valve, Valve Gasket Cover, all Spark Plugs, fresh oil, made sure that I followed the repair manual for my car. To no avail, I still had the exhaust smell and no mechanic could figure out where it was coming from.

This morning I decided to trade it for a newer 2012 Model! Look forward to pics in the newer Gen forums! I'll be posting any mods and such that I do to it!

Thank you for everyone's input and advice on trying to help the ole girl out, but she's retired now

-Alex