Kia Optima Forums banner
1 - 20 of 21 Posts

· Registered
Joined
·
1 Posts
Discussion Starter · #1 ·
I have just bought a Kia Optima and have never owned a GDI engine. I know the intake valves have to be cleaned every so often. My is how often and using the CRC intake cleaner how do I avoid the Mass Air Flow sensor. Question number 2 is can I use the vaccum line coming off the brake booster without hitting the MAF sensor.
 

· Registered
2011 Kia Optima
Joined
·
4,414 Posts
You can spray in right after the air cleaner assembly as Kia doesn't have a MAF sensor,
they have a MAP senslor. As far as frequency, take your pick, every 10, 20, or 30,000 miles.
I've never done it and the OEM engine lasted 172,000 miles and the replacement has
60,000 miles, no problems with the valves.
Not saying it should'nt be done, just stated that I haven't done it, just too lazy I guess.
 

· Registered
Joined
·
205 Posts
Is there a risk you will knock off some carbon pieces that fall into the engine and cause damage?
No not really the reside that sticks looks like tar and then hardens. The CRC is a good preventative measure but it will not remove a lot of the build up. The only real method is a walnut blast or another mechanical method since the deposits are sticky and hard.
 

· Registered
Joined
·
227 Posts
I have a new engine in my '12 Optima SX. I have an oil catch can on the pcv line, use GF-6 rated synthetic oil, a long life filter and change the motor oil every 4K. I also use Delco X66-A, sprayed into the pcv intake before every oil change (CRC is also a good product). I'm looking at getting a borescope to go with my X-Tool D8 and plan on checking the intake valves around 20K. I'm not sure how much blowby gets sucked in by the breather hoses but I've read it's around 10%.
 

· Registered
Joined
·
167 Posts
I have just bought a Kia Optima and have never owned a GDI engine. I know the intake valves have to be cleaned every so often. My is how often and using the CRC intake cleaner how do I avoid the Mass Air Flow sensor. Question number 2 is can I use the vaccum line coming off the brake booster without hitting the MAF sensor.
You can spray seafoam and use a fuel-additive all you want, the only true and proper/complete way to do this is walnut blasting.
As others have said, CRC is still helpful and you can do it in regular 15/20k intervals for optimal fuel economy and cleanliness.
 

· Registered
Joined
·
161 Posts
Today, I used the CRC Intake Valve Cleaner on our 2011 Optima EX, with 64000 miles and it WORKS!!!!
Firstly, we don't have a MAF sensor on our engines, so you can spray it directly into the intake hose. However, I chose to remove all the intake system to access (and check) the throttle body and butterfly mechanism. The good news was that our was really quite spotless. So I had SWMBO operate the throttle while I directed the CRC cleaner directly into the Throttle Body, following the instructions on the can. The motor did die a couple of times but quickly restarted....
I then put on the intake system and left it for just over an hour. We took it out to the Interstate to give it a "wide open" throttle but as I started it up outside the garage, a cloud of dark grey crud came out of the exhaust. Driving the 3 miles to the Interstate, it was a little "boggy" and slow to respond but when I got on the Interstate (75mph speed limit), I booted it and allowed it to hit the rev limiter. It was then that a huge cloud of dark grey crud came out of the exhaust!!!
I floored it all the way to the next exit (to turn around and head for home) and the motor ran up to just before redline in all the gears and so I put about 15 miles on it at serious speed.

Ok...the result is that it definitely idles smoother and the motor appears to be a little more responsive. After I did the cleaning, I also did an oil and filter change.
IMHO, it was well worth the $18 and time spent. Plus finding the Throttle Body and butterfly to be spotless was worth it in itself :) .
.
 

· Registered
Joined
·
205 Posts
Good on what used to be called the "Italian Tune Up. And I like the reference to
SWMBO as in Rumpole of the Baily.
Yea that wont work. Gdi injects fuel directly into the combustion chamber. Port Fuel injection sprays fuel in the intake port. The reason gdi valves get so dirty is that unlike port fuel injection there is no fuel air mix traveling over the back of the valve which constantly "washes" it. With gdi only air travels thru the port. The PCV redirects blowby gasses into the intake but without the constant fuel washing the back of the valve deposits build up.The deposits are like liquid tar and harden, the only way to remove them is mechanical removal. Your tune up method wont do anything. Solvents wont do anything. Jump on Youtube and look up humblemechanic he has a great video of the who what where and why on vw gdi build up and walks thru cleaning a gdi head. This is why Toyota has a hybrid method they have both port and direct injection. VW had major issues too so they changed the PCV system. You CAN minimize the build up with a catch can and using a high quality synthetic oil.
 

· Registered
Joined
·
161 Posts
I am fully aware of the different types of fuel injection.......and that to REALLY clean the Intake valves on a GDI engine, you need to strip it down and use a mechanical process.
Which is a fairly ridiculous expense if you don't have any real issues with the engine.

True. An Italian tune up won't work on its own but, following the treatment, CRC recommends a run at "highway speeds". And my highway speeds can be quite "brisk" :)

And, FYI, there are also video's out there showing the CRC treatment removing large chunks of valve grunge. But you really won't get them spotless using it, just a bit cleaner.

We still get a regular 34mpg highway on ours and 22 around town. It runs great but the idle was a little lumpy, so I decided just to check out the TB for cleanliness and also run a can of CRC through the system while I was at it. And, afterwards, I noticed there WAS an improvement in the idle and it smoothed out. Given the issues with the Theta II engines, I use Valvoline Synthetic 5w30 and Kia/Hyundai filters and change it every 3500 miles. So far, all the UOA's came back as normal and I hope that the sample I send off to Blackstone today comes back the same......

For the first 5 years, we used the Optima as a road trip car but, since we bought our Grand Cherokee, we now use it as our local runabout with the longest trips being 65 miles each way to San Antonio Airport. It has been as dependable as a hammer........using no oil between changes.

.
 

· Registered
Joined
·
227 Posts
For the GDI, I use Techron or other cleaners that have PEA (polyetheramine). Redline, Amsoil and a few other products also have PEA. For the intake valves I use the old tried and true decarboning product Delco X66-A (aerosol) or X66-P (pourable). I spray the aerosol into the pcv hose until the motor stalls and then let it sit for 15 minutes. When I start it again I spray the rest of the can into the running engine and then change the oil. I have a can of the CRC intake cleaner and a can of the MAF cleaner that I haven't used yet. Now, I know that the motor will likely blow up some time in the future, but if this cleaning keeps the intake valves and the pistons clean then maybe the new motor won't become an oil burner. It's an experiment in progress.
 

· Registered
Joined
·
205 Posts
For the GDI, I use Techron or other cleaners that have PEA (polyetheramine). Redline, Amsoil and a few other products also have PEA. For the intake valves I use the old tried and true decarboning product Delco X66-A (aerosol) or X66-P (pourable). I spray the aerosol into the pcv hose until the motor stalls and then let it sit for 15 minutes. When I start it again I spray the rest of the can into the running engine and then change the oil. I have a can of the CRC intake cleaner and a can of the MAF cleaner that I haven't used yet. Now, I know that the motor will likely blow up some time in the future, but if this cleaning keeps the intake valves and the pistons clean then maybe the new motor won't become an oil burner. It's an experiment in progress.
Keeping the valves and piston crown clean wont do anything about oil consumption. Oil consumption is due to the use of low tension oil control piston rings and the blow by. A piston soak with can help remove deposits that form on and in between the rings.
 

· Registered
2012 Black SX Prem. & Tech.
Joined
·
2,743 Posts
Keeping the valves and piston crown clean wont do anything about oil consumption. Oil consumption is due to the use of low tension oil control piston rings and the blow by. A piston soak with can help remove deposits that form on and in between the rings.
Do you have a recommendation, for the product and procedure to do the piston soak?
 

· Registered
Joined
·
227 Posts
Keeping the valves and piston crown clean wont do anything about oil consumption. Oil consumption is due to the use of low tension oil control piston rings and the blow by. A piston soak with can help remove deposits that form on and in between the rings.
That's why the engine is running at a fast idle while pouring or spraying the stuff in. It will go by the compression and oil rings and get behind the ring lands, where it is needed. Smell the oil after treatment. I've used this stuff for over forty years and it does unstick piston rings, depending on how much carbon is there. Along with crappy low tension rings, our cars have rather thin oil control rings and the pistons have small open areas where the rings are exposed to the crankcase.
 

· Registered
2017 Optima EX
Joined
·
239 Posts
A oil catch can is a must to intercept and trap all the oil vapor & crap going into the intake. Plus my 2017 seem to run better with a catch can. It helps to run very good quality oil and never run dyno oil. I use Redline oil.

The K5 store on this site sells a real nice CC. Here's my K2 with a homemade bracket so buy the bracket too lol.
 

Attachments

· Registered
Joined
·
6 Posts
I have just bought a Kia Optima and have never owned a GDI engine. I know the intake valves have to be cleaned every so often. My is how often and using the CRC intake cleaner how do I avoid the Mass Air Flow sensor. Question number 2 is can I use the vaccum line coming off the brake booster without hitting the MAF sensor. Speed Test
I have an oil catch can on the pcv line, use GF-6 rated synthetic oil, a long life filter and change the motor oil every 4K. I also use Delco X66-A, sprayed into the pcv intake before every oil change (CRC is also a good product).
 

· Registered
2012 Black SX Prem. & Tech.
Joined
·
2,743 Posts
I'm wondering if the total labor works out the same, for 1) removing the intake manifold and using the ziptie method to clean the intake valves once every 5 years, vs 2) installing a catch can and changing/emptying it every ??? months?
 
1 - 20 of 21 Posts
Top