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Spark Knock, still


lacseville

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I got my motor in and running fine...well finally. (intake gaskets and water pump replaced) I replaced the EGR solenoid and valve on my car and I still have spark knock. It's really pissing me off. I have almost no back pressure because of my exhaust. Could this be the problem? The valve has something to do with exahust backpressure and flow, right? I unplugged the solenoid sensor wire to allow the valve to open wide up and hopefully keep the combustion temps down, but no help. It still knocks. How about cold plugs, increased backpressure, or whatever? I've got to get rid of this any way possible. I'll completely not use the EGR if that's possbile.

not to mention, when i crank it up sometimes and when i rev on the throttle in park, i have BLUE SMOKE!!! WTF?! This is one sorry *smurf* reman engine. I keep thinking that it'll clear up when it gets "broke in", but I have about 800 miles on it now. The car smells like it's running rich. (19lb injectors) I replaced the intake manifold gaskets, so I'm sure of the bolt torque, I used AC delco plat plugs, and I replaced most of the vacuum lines. Could my ignition be too "hot" because of the Accel Super Coil and cap/rotor, and wires (i would not think so) Sorry for the length.

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Did you do anything with the time chain?

If you really want to make people safe drivers again then simply remove all the safety features from cars. No more seat belts, ABS brakes, traction control, air bags or stability control. No more anything. You'll see how quickly people will slow down and once again learn to drive like "normal" humans.

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I got my motor in and running fine...well finally. (intake gaskets and water pump replaced)  I replaced the EGR solenoid and valve on my car and I still have spark knock. It's really pissing me off. I have almost no back pressure because of my exhaust. Could this be the problem? The valve has something to do with exahust backpressure and flow, right? I unplugged the solenoid sensor wire to allow the valve to open wide up and hopefully keep the combustion temps down, but no help. It still knocks.   How about cold plugs, increased backpressure, or whatever? I've got to get rid of this any way possible.  I'll completely not use the EGR if that's possbile.

not to mention, when i crank it up sometimes and when i rev on the throttle in park, i have BLUE SMOKE!!! WTF?! This is one sorry *smurf* reman engine. I keep thinking that it'll clear up when it gets "broke in", but I have about 800 miles on it now.  The car smells like it's running rich. (19lb injectors) I replaced the intake manifold gaskets, so I'm sure of the bolt torque, I used AC delco plat plugs, and I replaced most of the vacuum lines.  Could my ignition be too "hot" because of the Accel Super Coil and cap/rotor, and wires (i would not think so) Sorry for the length.

Ok my 91 Seville ALSO had a spark knock for about a year. I may be wrong but I think you are describing detonation. Its more obvious on acceleration, worse then the car is really hot, but it will do it as you drive along also at times. It is a slight rattle, and the best high-octane gas in the world has no effect. It was annoying as hell and drove me crazy. As a matter of fact I was on the expressway the last week and I saw a beautiful 91 Seville and rolled the window down to look it over, and it also had detonation. That rattle I had caused me to research the problem and bbobynski was very helpful and knowledgable about it. I will try to find the information or link and post it for you but it was from the old caddy board.

Anyway, you dont say whether or not you cleaned the EGR tubes that face up when you look down the throttle body. If you have not cleaned them yet, clean them thoroughly.. I used round brass and steel brushes, compressed air and carb cleaner, with the EGR valve off and a rag over the EGR holes. I got the round brushes at a gun shop they are gun cleaning brushes. I cleaned the hell out of those tube.. I also cleaned the EGR valve seat and pindle with carb cleaner being EXTREMELY careful not to get the cleaner on the diaphram or in the vacuum port. In addition, I pulled the TB off, cleaned the plates, replaced the gasket, replaced all the vacuum hoses with OEM hoses etc. The result was it was better but not perfect yet... I was "BROWSING AROUND" in my local Cadillac service department talking to a few mechanics while I was getting parts one day, and the tech said "REPLACE THE EGR VALVE" they are near impossible to clean.... Replaced it, DETONATION GONE... hey it had 90,000 miles on it, it was time!! Buy a new EGR, after you have cleaned and eliminated everything else mentioned above (tubes, TB plate, vacuum problems), get a price from these guys, www.gmotors.com Let me know how it turns out, I miss my 91... Mike

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oh, i guess i need to catch you guys up! I got a new Jasper reman motor. I still have my old motor (timing chain still broken!) in my shop. Since I got this motor I've had nothing but trouble. I, first, had to replace the intake gaskets (coolant in oil). then i had to replace the water pump. (overheated) Now I'm getting some blue smoke and detonation. Yes, scotty, that's most likely what I've got. You described exactly what happens. So, none of the EGR tube cleaning would help, because it's a new motor with 800 miles on it. I just cleaned my EGR valve, but I'll purchase a new one and see if that helps. I've checked and checked again the timing. I was running 13* and that was awful. Now I"m at 9-10 and it's better, but still bad. Thanks for the suggestions. If someone happens to have one in stock, I'll let you know tomorrow.

scotty, if my car keeps up like this, i may have a 91 sev you could buy very cheap, very soon!

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oh, i guess i need to catch you guys up!  I got a new Jasper reman motor.  I still have my old motor (timing chain still broken!) in my shop.  Since I got this motor I've had nothing but trouble.  I, first, had to replace the intake gaskets (coolant in oil).  then i had to replace the water pump. (overheated)  Now I'm getting some blue smoke and detonation.  Yes, scotty, that's most likely what I've got.  You described exactly what happens.  So, none of the EGR tube cleaning would help, because it's a new motor with 800 miles on it.  I just cleaned my EGR valve, but I'll purchase a new one and see if that helps.  I've checked and checked again the timing.  I was running 13* and that was awful.  Now I"m at 9-10 and it's better, but still bad.  Thanks for the suggestions.  If someone happens to have one in stock, I'll let you know tomorrow.

scotty, if my car keeps up like this, i may have a 91 sev you could buy very cheap, very soon!

Good, that is what I would do, if that is your old EGR, I would replace it. One more thing however, I did have to replace my CAT also, I don't know if that contributed to it due to restricted exhaust raising the exhaust temp, hows the CAT? Does it rattle? However my memory tells me that it was the EGR valve. Did I see you state that you disconnected the vacuum hose to the EGR or disconnect the EGR solenoid? If the EGR is old, they are difficult to clean and the pindle could be hanging open due to a fused-on deposit.

I can tell you that when it was fixed, the detonation was gone for good. Mike

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well, i replaced the egr valve. it helped, but it's still there. i can hear it right after it upshifts from, say, 2-3. only when the engine is lugging. like i said, it did help it a lot, but it's still doing it. I have no cat. I have a tiny glasspack in it's place and a magnaflow on the end (2.5"pipe throughout) Would the TPS setting have anything to do with this? One time my TPS was way off and it knocked something terrible. I never really "correctly" set it, I just put it to where it ran the best.

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well, i replaced the egr valve.  it helped, but it's still there.  i can hear it right after it upshifts from, say, 2-3.  only when the engine is lugging.  like i said, it did help it a lot, but it's still doing it.  I have no cat.  I have a tiny glasspack in it's place and a magnaflow on the end (2.5"pipe throughout)  Would the TPS setting have anything to do with this?  One time my TPS was way off and it knocked something terrible.  I never really "correctly" set it, I just put it to where it ran the best.

You need to make sure the EGR circuit is operating. Are you getting an EO48 code at all or any other codes? Try disconnecting the battery and letting the system go through a re-learn now that you did the EGR, by the way, was it an OEM EGR, they are calibrated for the 4.9 bbobynski has confirmed that, a generic EGR may cause problems. What kind of gas are you using and what is your normal operating temp? I don't think the TPS could cause this its usually related to stalling and racing idle problems, but I am not sure. At idle you can check your TPS adjustment have you done that? There is a very specific adjustment procedure for the TPS that involves the Minimum Air Adjustment at 500 RPM. Do you have the manual? Mike

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yes, i've got the manual. i'm trying to perform the specific tps procedure, but i keep getting hung up on the checking something else while in an override. normal operating temp is about 186 on the highway and 213 around town (180* tstat) I did get a generic egr valve. it had a few washers with it that i was supposed to pick the correct one. I even had to twist the head around 180* to get the vacuum lines to line up... i wanted a delco, but all they had in stock was the "wells" brand. I always use 93 octane. no brand loyalty, just whatevers closest when i need gas. I will disconnect the batt.

here's a list of what i've done, maybe it'll help diagnose:

new jasper reman 4.9

accel cap/rotor

accel hei super coil

msd 8mm spirals

AC delco plat plugs

short ram intake (sucks hot air though behind radiator though)

19lb camaro injectors

18" resonator w/ magnaflow muffler 2.5" manifolds back

180* tstat

blue smoke (wtf?)

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Why are you using a 180* thermostat??? I thought the proper stat was 190*???

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

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it is, when i got it, i thought i was doing my engine a favor, but i've known for a while that it needs to run warmer, i just haven't changed them out. doesn't seem to be hurting anything for now!

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yes, i've got the manual.  i'm trying to perform the specific tps procedure, but i keep getting hung up on the checking something else while in an override.  normal operating temp is about 186 on the highway and 213 around town (180* tstat)  I did get a generic egr valve.  it had a few washers with it that i was supposed to pick the correct one.  I even had to twist the head around 180* to get the vacuum lines to line up...  i wanted a delco, but all they had in stock was the "wells" brand.  I always use 93 octane.  no brand loyalty, just whatevers closest when i need gas.  I will disconnect the batt.

here's a list of what i've done, maybe it'll help diagnose:

new jasper reman 4.9

accel cap/rotor

accel hei super coil

msd 8mm spirals

AC delco plat plugs

short ram intake (sucks hot air though behind radiator though)

19lb camaro injectors

18" resonator w/ magnaflow muffler 2.5" manifolds back

180* tstat

blue smoke (wtf?)

Yes the stat is a 195, you need to change to a 195. Detonation is mainly due to a lean mixture, that is why the EGR stuck open causes detonation. Check for vacuum leaks. Again, I would disconnect the battery and let the engine go through a re-learn procedure. I would also check and set the static timing, did you install the distributor? Did you use new TB gasket when you installed the throttle body. How is your fuel pump pressure? Read this article , Mike

http://www.misterfixit.com/deton.htm

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alright, i will change to a 195; geeze you guys, back off... ;) i have 2 more hoses to replace and disconnect the batt. not sure i have enough fuel, will also tape gauge to the hood and check er out. i did install the dist, and used a new gasket when i installed TB, but have taken it off a couple times now and just put it back on. i'll let ya'll know how it turns out. thanks.

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Check fuel, check to make sure the distrubitor is set right.. i've seen people have it wayyyyy off and the car still runs just not very well. And check fuel and your 'camaro' injectors :>

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Noticed you were using a "Wells" aftermarket EGR valve. After the local place started stocking Wells brand I switched to a different place. Parts looked really cheap. I used a Wells O2 sensor in my old Ford van. Wells listed the replacement as on of those "one size fits all" sensors. It fit OK, but it just didn't work. Now I only use OEM or NAPA if OEM is unavailable. You might want to revisit the EGR issue with an eye toward going back to OEM. That business about using washers and turning the head around is troubling.

FWIW

YMMV

DFB

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NAPA stuff always seems to work for me.. They have good parts.. most of the time I end up paying the same or even more than OEM for napa parts but I've never had a problem with them and they usually include extra 'features' like grease fittings where they apply and stuff like that that the OEM doesn't have. The thermostat has nothing to do with detonation (except that eventually if running cold enough it will cause carbon buildup if you don't WOT a lot).. You better hope it's just detonation and not preignition :/ preignition destroys stuff

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okay, got some new stuff... I did the min air idle procedure, set the tps min and max, did idle relearn (everything was off) I took the batt terminal off for about 5 mins, reconnected and drove. i still have detonation (i think that's what it is) I even set the timing back to about 6-7*... it's still there; not as bad, but right after the upshift under load. I replaced all the remaining vacuum lines. I noticed today that I forgot that my PCV grommet is in bad shape. I need to replace that. Could that be causing anything?? probably not?

Also, on the smoke issue, if i rev it to where it's "clear", it only spits out smoke at the top of the a rev. It appears again at the bottom of the decleration. does this sound like valve seals?

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look at my dist... it's not exactly faced the same direction as before, but the timing is correct. it's off a tooth i think, but the timing is still correct.

post-3-1092097840.jpg

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  • 8 months later...

From what I can see, your distributor position is wrong and needs to be corrected, see this thread. This is a LONG thread but read it through, the distributor section it toward the rear.

http://caddyinfo.ipbhost.com/index.php?sho...l=to%20tdc&st=0

QUOTE from thread >>>The HEI distributor serves two purposes. Spark, and to tell the PCM what the cam position is. The 4100 HEIs are unique because they have a pickup coil for the ignition module AND a hall effect sensor to tell the car what position the camshaft is at.<<<

This photo is from my 91 4.9 Seville Service manual, they are very particular about the direction the distributor faces.... see that thread, I have more photos there

post-3-1114530492_thumb.jpg

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