Engine/Transmission (1994 - 1998) high EGT's

[Heepdriver]

We cut the cam plate and slid it forward on my buddies 95 auto. He shortly there after blew up his stock turbo on the exhaust side, and ended up with a piers HX-35/40 combo turbo with banks 4"elbow and 4" exhaust. We don't know much about the truck he baught it 2 years ago. But it has always run strong. It had a 16cm housing on the stock turbo.



Now that he has been running the new turbo for a month or so his EGT's have gone up to 900 degrees at cruise on the highway, unloaded and lite on the pedal. we thought he had a boost leak, because he blew the pass. side hose off on the first test drive with the new turbo, but he is still making 42#s of boost if he romps it. And he says its not hissing like it was when he blew the hose off. Just running real hot. oh he says when he romps it it spikes to like 1200 and his probe is after the turbo. and the turbo is wastegated at 42#'s. and his big honkin air filter just went on yesterday. any ideas of places that are hard to see that you know of would great. anyone know how to test the intercooler for leaks. how much pressure and for how long. can you pressureize the intake with it to see if your gaskets are leaking?





on a side note I just installed my 4" exhaust and BHAF today and am now making 33#'s of boost. lost kitty, missing muffler Oo.

 

[bmoeller]

Is he hitting 1200*, empty, standing on the skinny pedal? That's a lot for being post turbo. Sounds like not enough air/boost leak.



What kind of profile did he grind on the plate? How big are the injectors? What turbine housing is on the new turbo?



You can use regulated shop air to test for leaks. 20-30# ought to be more than plenty.



The lower intercooler boots have a tendency to get rubbed through, from the sheet metal on some trucks.



Other than a leak in the intercooler, CAC hoses, gaskets on the intake horn or under the plate on the manifold. There is also the rubber o-ring, on the aluminum elbow, off the turbo.



Since he is hitting 42#, I doubt he has a leaking exhaust manifold/exh. gaskets.

 

[JKaltenheuser]

I have a similar problem when i slide my #10 plate ahead my egts will hit 1500 degrees pre-turbo, is it safe to run these kinds of temperatures bmoeller? I went to the truck pull last weekend and i was the only guy there with a cummins and i got my but kicked by powerjokes and duracraps so i have to have more power.

 

[bmoeller]

Generally, from what I've read 1200-1250 sustained is OK. 15 is not. I've seen up to maybe 16-1700* (on the dyno, gauge stops at 1500)) briefly. The metal isn't going to get that as quick as the air.



http://dodgeram.org/tech/dsl/FAQ/turbo_faq.htm



Scroll down about halfway for the EGT chart. I'd sugest reading the rest of that page, too. Lots of good info.

 

[bluthndr]

I have had mine pegged (1600+ pre turbo) many times for maybe 3-4 seconds, and so far so good.

 

[Heepdriver]

Is he hitting 1200*, empty, standing on the skinny pedal? That's a lot for being post turbo. Sounds like not enough air/boost leak.



What kind of profile did he grind on the plate? How big are the injectors? What turbine housing is on the new turbo?



yes he is hitting 1200 plus unloaded standing on the skinny. it did not do this for about a month after the turbo was put on.



the profile I ground on his is the same as mine. I cut from just under the fuel stop bump in a gradual slope to the above flat area and taper the radius's. This way the original governor arm contact area is preserved, other than being slid forward. not to much initial fuel until the boost comes on, then i imagine its like a 0 plate.



his original xhaust housing was a 16 cm wastegated? not sure

the housing had a 16 cast into it, it could be a 12 like stock

Now he has a 14cm wastegatedhousing

no idea about the inj. size they were in and had been replaced but no one seems to know how big they are.

his Afc was unhooked when he baught it if this helps.



thanks

 

[bmoeller]

yes he is hitting 1200 plus unloaded standing on the skinny. it did not do this for about a month after the turbo was put on.

So it didn't it right away. Just strarted recently, correct? If so, it sounds like a boost leak.

the profile I ground on his is the same as mine. I cut from just under the fuel stop bump in a gradual slope to the above flat area and taper the radius's. This way the original governor arm contact area is preserved, other than being slid forward. not to much initial fuel until the boost comes on, then i imagine its like a 0 plate.

How hot does yours run?

his original xhaust housing was a 16 cm wastegated? not sure

the housing had a 16 cast into it, it could be a 12 like stock

12cm2 is stock.

Now he has a 14cm wastegatedhousing

When was the housing installed? If it isn't a boost leak, it may need a 16. Could be to small for the top end, choking it off a bit.

no idea about the inj. size they were in and had been replaced but no one seems to know how big they are.

Will have to pull them, to find out what they are. Numbers on the injector body and a different number on the tip itself.

 

[Heepdriver]

So it didn't it right away. Just strarted recently, correct? If so, it sounds like a boost leak.



That's what I thought, boost leak. but we haven't found it yet. And he can still open the wastegate at 42#'s



How hot does yours run?



I was able to hit 1150 unloaded standing on the skinny@ 29#'s of boost no wastegate. now I have a 4" straight pipe and BHAF and have not seen over 950 @ 33#'s. I have a high flow frt bumper with a wing under the intercooler to draw more air up to the intercooler. all my temps seem to stay extra cool. I do block off for winter highway driving.



12cm2 is stock.



sorry I miss stated that, yes 12 is stock. his had a 16 cast into it. I do not know if that is just a casting number. or the CM2. I would assume CM2 but *** u me ing is never good.



When was the housing installed? If it isn't a boost leak, it may need a 16. Could be to small for the top end, choking it off a bit.



the housing on it came with the turbo, used bought out of georgia off of here.



Will have to pull them, to find out what they are. Numbers on the injector body and a different number on the tip itself.

He is not going to let me pull his inj. I know him that well. I'm wondering about sliding the cam plate back. but it wasn't doing this a couple weeks ago.



I also thought about I worked on a Ford P/s once that was making the boots inflate enough to thin out the area under the clamp and allow a boost leak that would reverbirate. maybe he needs to call piers for some boots.



thanks

 

[bmoeller]

I've blown boots off before, but it was on a big truck. Had to replace the clamp, in that case.



The newer style of boots wouldn't hurt. Sliding the plate back would be a good idea.

 

[Midnite]

Is it possible the pump timing has slipped and retarded slightly? Probably very unlikely if nobody's been working on the pump recently.



Regardless, if the pump timing is still stock it's probably begging for some advance.



Mike

 

[Heepdriver]

I'll ask him about the timing. is it starting hard or running rough. I just had the go round with setting mine. His had been set just before he baught it. along with the injectors a head gasket and a full service details were always a little fuzzy. Now we have found and learned that he had a 16cm ex. housing and larger injectors. Who knows what the dilivery valves or the Governor springs are. His truck has always ran strong and smooth. Wound up to higher rpms right from the get go. now that you mentioned it my truck ran smoother with the timing retarded and had higher egt's.



thanks for all the ideas