bigjayzway Posted July 2, 2005 Report Share Posted July 2, 2005 I always run 93 or better octane in my 94 Deville, with the 4.9 engine. I thaught I had got some bad gas, but 4 tanks later.....she is still pinging. When I put a slight load on it, going up hill, or passing without nailing it...I wonder if you can adjust the timing in this motor? Oh yeah, I am on the 4th GM O2 sensor now, and I am getting the code for it again!!! Life is too short to grow up! Link to comment Share on other sites More sharing options...
navion Posted July 2, 2005 Report Share Posted July 2, 2005 bigjayzway, Did you replace both O2 sensors? There is one on each side of the engine. I can't remember if there are more by the cat on the 4.9. Some vehicles have as many as four O2 sensors. One for each cylinder bank, a precat and a post cat sensor. Check your manual. Britt Britt Link to comment Share on other sites More sharing options...
adallak Posted July 2, 2005 Report Share Posted July 2, 2005 I always run 93 or better octane in my 94 Deville, with the 4.9 engine. I thaught I had got some bad gas, but 4 tanks later.....she is still pinging. When I put a slight load on it, going up hill, or passing without nailing it...I wonder if you can adjust the timing in this motor? Oh yeah, I am on the 4th GM O2 sensor now, and I am getting the code for it again!!! Your pinging is most likely caused by lack of exhaust gas flow when engine is hot (180 plus). Plugged EGR passages, lazy EGR valve are common sources of ping under slght acceleration. When engine is hot at slight throttle the ECM changes timing assuming you have enough EG flow to cool down the combustion chambers, but if you do not you get spark knock. If you accelerate harder the ECM does not change timing and EGR is disabled too so you do not get spark knock. Do you have pinging when engine is cold? O2 sensor might be the culprit too, but inspect the EGR tubes, EGR valve, EGR solenoid first for proper operation. This subject was discussed earlier. I have the knock and narrowed it to EGR valve but did not replace it (no time as usual ) Since that knock is benign and just annoying i left it as is for now. The saddest thing in life is wasted talent Link to comment Share on other sites More sharing options...
bigjayzway Posted July 2, 2005 Author Report Share Posted July 2, 2005 You know, I took the EGR off and cleaned the hell out of it. Everything looked sparkling clean 3 days ago. I cleaned it, cause I had a P048 code. Well the code is now gone, but the ping is still there when it is hot.... I am so tired of the 02 sensor, and finacially, I can't keep replacing them. Like I said 4 of them now, so I can't figure it out, even my mechanic is frustrated with the situation. I never let him go in blind either, I always come here first and tell him what needs to be done....he too loves this site. His shop NEVER touched Cadillacs before me, and still won't work on anyone elses other than mine. Life is too short to grow up! Link to comment Share on other sites More sharing options...
adallak Posted July 2, 2005 Report Share Posted July 2, 2005 big, Cleaning tubes will elilinate 48 code BUT the ping will be still there. Here is a test. Connect the vacuum hose throm TB body dierctly to EGR valve (bypassing the EGR solenoid). You will get very poor idle maybe even stall (resrat the car if stalls), but you'll be able to drive around the block. Get operational temperature and slightly press gas pedal you'll see there will be NO knock since bypassing the EGR solenoid provides the EGR valve with a lot of vacuum and it opens up allowing EG flow to combustion chambers under slight throtle. If you figure out it's the EGR valve you can replace it AND the gasket or just leave it alone as I did. BTW, I have been using 89 for two years with no loss of power or fuel economy. A lot of people use even 87 with the same result. In the case of 87 you better change the timing to 6, but I would not do anything for 89. The saddest thing in life is wasted talent Link to comment Share on other sites More sharing options...
Scotty Posted July 2, 2005 Report Share Posted July 2, 2005 This is DEFINATELY detonation and NOT low octane pinging... even though it sounds the same. The giveaway is that it occurs on light pedal. It is imperitive that you clean the 2 EGR ports that you see when you open the TB and look in.. The BEST way to do that is to PULL the EGR valve off and clean them with the EGR off, use carb cleaner or upper engine cleaner that is safe for O2 sensors and ROUND wire brushes, they make round wire brushes for GUN cleaning and for cleaning crankshafts. Use compressed air and after you clean the hell out of the tubes blow out the tubes, COVER the EGR port (where you took the EGR off) with a rag so you don't blow solvent all over. Check ALL vacuum hoses for proper routing and for cracking. Now I know that MANY say you can CLEAN your EGR but in reality they get to the point where cleaning just does NOT work. Replace it with an OEM EGR valve NOT an aftermarket EGR.... check this site for prices www.gmotors.com It took me over a year to get rid of my ping, once I replaced my EGR it was GONE... THis has NOTHING to do with overheating, timing or low octane, its a LACK of EGR flow... and its DETONATION Link to comment Share on other sites More sharing options...
Scotty Posted July 2, 2005 Report Share Posted July 2, 2005 Another view of EGR/TB Link to comment Share on other sites More sharing options...
Scotty Posted July 2, 2005 Report Share Posted July 2, 2005 Here is a good article on Detonation and Preignition http://www.misterfixit.com/deton.htm Link to comment Share on other sites More sharing options...
Scotty Posted July 2, 2005 Report Share Posted July 2, 2005 Thats true but I associate pinging with pre-ignition and low octane, and detonation is different. That is why I posted the link detailing the differences between detonation and preignition. Link to comment Share on other sites More sharing options...
canadian95sts Posted July 2, 2005 Report Share Posted July 2, 2005 even my mechanic is frustrated with the situation. I never let him go in blind either, I always come here first and tell him what needs to be done....he too loves this site. His shop NEVER touched Cadillacs before me, and still won't work on anyone elses other than mine. AHEM!!!!! Big Jay, i believe Eddy B also enjoys working on my STS, MEMBER!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Always forgotten EH!?!?! heres our mechanic hard at work, A good friend will come and bail you out of jail...BUT, a true friend will be sitting next to you saying, "darn...that was fun!" www.madd.ca Link to comment Share on other sites More sharing options...
canadian95sts Posted July 2, 2005 Report Share Posted July 2, 2005 He really is an excellent mechanic, only one i trust with my STS A good friend will come and bail you out of jail...BUT, a true friend will be sitting next to you saying, "darn...that was fun!" www.madd.ca Link to comment Share on other sites More sharing options...
Ranger Posted July 2, 2005 Report Share Posted July 2, 2005 I guess it's painfully obvious that the days of climbing in the engine compartment to work on things are long gone Link to comment Share on other sites More sharing options...
adallak Posted July 2, 2005 Report Share Posted July 2, 2005 The saddest thing in life is wasted talent Link to comment Share on other sites More sharing options...
motor_car Posted July 3, 2005 Report Share Posted July 3, 2005 No, they are not Cheers Link to comment Share on other sites More sharing options...
motor_car Posted July 3, 2005 Report Share Posted July 3, 2005 I had same kind of part throttle pinging on my 4.5l in the 1988 Seville. Only a new EGR valve solved the problem.. Cheers Link to comment Share on other sites More sharing options...
canadian95sts Posted July 4, 2005 Report Share Posted July 4, 2005 OK I bypassed the sensor, and I no longer have a ping! I must say, it sounds like I put an aftermarket cam in it now. I do know now I don't need a new EGR I need the sensor! Thanks guys, you are all a great bunch!!! A good friend will come and bail you out of jail...BUT, a true friend will be sitting next to you saying, "darn...that was fun!" www.madd.ca Link to comment Share on other sites More sharing options...
adallak Posted July 7, 2005 Report Share Posted July 7, 2005 OK I bypassed the sensor, and I no longer have a ping! I must say, it sounds like I put an aftermarket cam in it now. I do know now I don't need a new EGR I need the sensor! Thanks guys, you are all a great bunch!!! But now you'll have poor idle. The saddest thing in life is wasted talent Link to comment Share on other sites More sharing options...
bigjayzway Posted July 7, 2005 Author Report Share Posted July 7, 2005 I replaced the solenoid, and cleaned the tubes today!!!!!!Yeah no more ping, or sevice engine light!!!! You guys ROCK!!!!!!!1 Cheers Big Jay!!!!!!!!!!!!!!1 Life is too short to grow up! Link to comment Share on other sites More sharing options...
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