New Engine? [Archive] - Diesel Place : Chevrolet and GMC Diesel Truck Forums

: New Engine?


js3350z
01-06-2007, 11:27 AM
I just took off the intake to install a boost gauge, and there was some oil sitting in the turbo and A LOT of carbon buildup in the intake, we called a local place, and they said it may be blowby from the engine and they reconmended a new engine...

so do you guys have any ideas on this, or do I really need a new engine

FastCR
01-06-2007, 11:35 AM
replace CDR. It's probably just stuck.

Dan Hunter
01-06-2007, 11:42 AM
Read any thread on gutting the upper intake plenum. It's the nature of your engine that some oil moves through the CDR and back into the engine. The buildup is a mixture of soot from the EGR and the oil from your crankcase. Until you block the EGR (two choices on method really; search threads), it'll continue. Harm of its presence is a matter of opinion and conjecture. Bottom line: that's the way it's supposed to look.

For fun, ask them how that oil got there and why it's a problem and listen for BS in the answer. They're selling you something you almost certainly don't need.

js3350z
01-06-2007, 12:24 PM
so to block my EGR (thing on top of the intake) I can just make a thin steel plate to fit under there...

that is what a picture looks like

teroma25
01-06-2007, 12:25 PM
Read any thread on gutting the upper intake plenum. It's the nature of your engine that some oil moves through the CDR and back into the engine. The buildup is a mixture of soot from the EGR and the oil from your crankcase. Until you block the EGR (two choices on method really; search threads), it'll continue. Harm of its presence is a matter of opinion and conjecture. Bottom line: that's the way it's supposed to look.

For fun, ask them how that oil got there and why it's a problem and listen for BS in the answer. They're selling you something you almost certainly don't need.

Ditto on that one!
Man I got so much blowby on mine, sometimes you'd think its on fire, lol.
Blowby is normal, mine is a little excessive and I'm sure it will give up someday, but until then ....

js3350z
01-06-2007, 12:42 PM
I kept looking through otherposts, and can't really fully understand...

am I just totally blocking off the flow, I am going to be getting a new computer so I guess I will be provideing an "F" vin as a few other posts say, so what am doing with the wire connecting and the little tube

Dan Hunter
01-06-2007, 01:09 PM
OK, your Exhaust Gas Return really is more of a intake air charge heater used to assist cold starts; without it, ALL exhaust gas would go out the tailpipe. Once the engine is warm, it's closed unless soot has jammed it open and for most people the benefit the EGR provided to get the engine to pass EPA standards when spanking new isn't worth the risk of failure and blocking is easy.

Small ports on your heads direct a small amount of exhaust gas into ducting on your intake that then flows up a round port in the center of the lower intake plenum. This is where the mystery gasket fits to seal the upper and lower intake plenums and this is where some folks put an 45mm freeze plug.

The otherwise unplugged ducting continues up through the upper intake plenum and into the actual EGR valve - the ugly rusty cast thing with a vacuum line attached to it. The EGR is a vacuum actuated piston that uses ports - much like a 2-stroke engine brings fuel/air into the crankcase - to vent relatively small amounts of gas into the intake when necessary. Placing a blockoff plate between the upper intake and the EGR effectively stops the flow.

There are those that prefer to use gaskets between the intake and head from non EGR assemblies to block the gasses at the head to eliminate heat coming into the intake and heating the air charge. Personally, I'd have to see some measureable results to warrant that much effort. Maybe if you're already pulling the intake but I don't tow the the edge of acceptable EGT to make this worth the effort.

gmctd
01-06-2007, 01:26 PM
EGR is used to lower oxides of noxious at certain operational events, such as decelerating from highway speeds to residential speeds, or no APP input when rolling down long grades - anytime conditions demand extended deceleration.

This also serves to add color to the blowby oil in your intake - black, sooty color, to be specific.

If you remove the intake manifold from the engine, it can be cleaned with Diesel fuel, then hot soapy water - cup of laundry detergent to 5gal hot water will flush the sooty Diesel fuel off, then rinse with clear hot water, and it will all quickly dry.

Dan Hunter
01-06-2007, 01:49 PM
Crap, wrong again! Someone take my keyboard away from me.

gmctd
01-06-2007, 02:18 PM
Not so, Maj - the EGR system is also used to heat the intake manifold to get the intake air within spec'ed emissions parameters shortly after cold-start.

Problem is, that added heat doesn't go away as ECT increases, or ambient temps increase, or underhod heat increases with ac operation, etc.

Sorry - guess you'll have to get your keyboard back out, and stay in the game

Snoddytn
01-07-2007, 01:12 PM
so when you install a boost gauge and pull off the upper intake is there a gasket that you have to replace on it? If so can I get that at Advanced or Auto Zone or do I have to go to the dealer

chrisk1500
01-07-2007, 02:07 PM
There is a gasket between the upper and lower intakes.....dealership carries them for around $15....I couldn't find them anywhere else.....might be different in the States though...

DavidPhillips
01-07-2007, 02:14 PM
The lower intake along with the upper intake that is made for a non-egr engine makes a lot of difference in air flow as well as the heat mentioned. After changing mine out I think it was well worth it and would do it again.