April 01, 2012

Problem With Direct Injection Engines

One of the problems with direct injection (+ turbo) engines like EP6-DT engine family, is getting excessive tar like coating in the intake manifold, and a nasty carbon build-up on the back of the intake valves once the car had clocked around 50,000km as shown below - hence one of the contributing factors to the infamous knocking problems.

For instance, (unlike port injected engines) direct injection engines can not make use of additives with cleansing agents found in fuel to clean and prevent tar-like substance and carbon build-up around intake manifold and intake valves because the fuel is injected directly into the combustion chambers without passing through 'em.Where did this 'black substance' come from?
It's the burnt oil vapour coming from the positive crankcase ventilation (PCV) system.

This problem can however be eliminated. Click HERE for the solution.


Good Luck!

15 comments:

shithappens said...

uncle...what wud this 'mod' likely to do to our 308? top of my mind, wud this resolve the knocking issue??

do u think the fellas at SC will 'approve'?

thanks

Wan A. Hadi (one.D) said...

I've contacted a manager at a Pug SC. He buys the idea and is looking forwards.

'Deleting' the PCV may reduce substantially the possibility of tar-like substance and carbon build-up around the intake manifold for sure and hence the 'normal' knocking issue but I think 'super' knocking associated with the timing mechanism definitely not.

hasnul said...

salam uncle. how r u doin? i've read ur posting in autoworld forum that u hv replaced ur car's timing chain. may i know at whch SC was it done. KS told me they dont do warranty claim anymore. I was advised by the SA to replace it elsewhere. went to service @ SC balakong, but they say its ok. The SC is quite new & i dun have much faith in them yet.

BTW, why did u replace ur timing chain? My car is nearing its end of warranty coming June, so i wud hope to replace any defective parts before then

Wan A. Hadi (one.D) said...

wms Hasnul,
Very true some if not all authorised Peug SAs are no longger doing warranty claim.

BTW, Click HERE for the reason why I replaced the timing mechanism...

paan said...

so how bro? engine no problems after doing this?

kL said...

does installing an oil catch tank help?

Wan A. Hadi (one.D) said...

Paan...
Almost 1 month already. So far so good. No more infamous fault code detected with "Lion Heart" diagnostic s/ware.

On April 27th will be driving to Kelantan to test the car for approx. 450km non-stop ... as well as to stay far away from the Bersih 3.0 hahaaa...

KL...
whatever means to prevent/reduce oil vapour from passing through intake manifold into the combustion chamber will help, of course.

Sun said...

helloe uncle :) ..i just got my 308turbo 3weeks ago. I have been reading around and got to know about engine knocking. With this new add on/modification,can this be done by myself and will this void the warranty? I have shared this with SC Balakong and they informed that they are not aware of such cap from Peugeot, maybe not yet. May i know where i can get this cap so i can install it on my 308T?

Btw, as a new owner of a 308T, your blog as been tremendously informative to me and appreciate your effort on the updates to share with all your fellow readers.

Wan A. Hadi (one.D) said...

Sun...
click HERE

Sun said...

Thank you, i will call and check with SC.

paan said...

bro, how did u manage to get to the plugs at the intake manifold?

zubairauto said...

Salams uncle.d, gud luck on the test run nnt.. Hehehe, nnt i move back kl year end kite boleh mini tt

Tak cadangkan pakai Caltex uncle? Kan nnt ader org cuci piston dlm injin kalo isi minyak dier, kasi clean carbon build up :-)

jonny said...

Hi just want to ask how to differentiate between normal knock and super knock?? Keke

NANS said...

A bit concerned regarding closing up the crankcase ventilation since the pressure buildup in the crankcase can cause gasket failure due to pressure buildup.
Indirect injection obviously washes off the oil from the valve backs and the ports and keeps them clean.
I wonder what other manufacturers such as mercedes Volvo Audi VW with GTDI(gasoline turbo direct injection) are doing to counteract this problem, perhaps a smaller amount of blowby gases mixed in with the intake air? or perhaps higher up in the upstream part of the intake air closer to the turbocharger?

Anonymous said...

NANS, it seems that they add an air pump to solve the issue.

http://www.supramania.com/forums/showthread.php?96628-PCV-system-explanation-and-mod

I am going to get a 308 THP soon! First continental car so am very excited and reading up on it.

From what I have read, just removing the PCV return hose and capping them off is not the ideal technique. Possibly fitting a catch can between the intake manifold and engine should solve the long term carbon buildup on the intake valves/manifold.

However, it won't solve the blow-by which leads to +ve pressure in crankcase. Now a catchcan and a pump may work together to keep the PCV return hose clean and maintain vacuum when you floor the pedal. I think the the vacuum pressure created cannot be too strong either or bad things happen...

But where to put the pump? And how much vacuum pressue? I don't know enough about this engine yet.
AHW we need your expertise.

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