4.6L LD8 , L37 Engine Replacement Guidelines - DTC powertrain vehicle oil consumption noise leak
| Subject: | 4.6L LD8, L37 Engine Guidelines for Engine Replacement. |
| Models: | . |
When servicing the vehicle with the VIN you entered, the following diagnosis might be helpful if the vehicle exhibits the described symptoms.
Condition/Concern:
00-03 Cadillac EB KB 4.6L (LD8) (L37) Engine guidelines for engine replacement.
Recommendation/Instructions:
Most of the engine symptoms should be able to be repaired, as noted below, with two exceptions, block porosity, and block damage, holes or mount bosses broken off.
Coolant Leak, block porosity - it is usually in one of 2 places, behind the engine mount bosses, or in the valley where the starter is. The engine must be replaced for this concern. A comment maybe made that the cylinder bore has excessive taper or is oversized or oval or had excessive piston to bore clearance. The technicians are measuring it in an unloaded state(cylinder head is off) and the dimensions will change. They should proceed with either the piston or ring replacements. These will repair the cold knock or oil consumption concerns. The new pistons and rings take into account that dimensions of the cylinder have changed somewhat and will work in these applications.
| • | Engine noise on a cold start. Replace piston per bulletin 03-06-01-025. |
| • | Oil consumption, follow bulletin 02-06-01-009C. Be sure to note what was the oil consumption rate before and after the cleaning process outlined in the bulletin. The guideline is 1quart in 2000 miles for a vehicle in warranty. If a vehicle has 65,000 miles and it uses 1 quart in 1800 miles this would be acceptable, some oil usage will occur as mileage increases. If the vehicle still has a high consumption rate then install the rings, they are designed to work with the irregular cylinder bores. Note, the cylinder bore surface does not need any mechanical preparation when installing new rings. |
| • | Head gasket leaks/ damaged threads in the block. The time sert process will repair the threads and can be reassembled. The revised head bolts torque spec also reduce the load on the threads. |
| • | When disassembling, crank case bolts that break when removing them. There are time serts available for that thread as well if they are damage during the process of removing the damaged bolt. |
| • | Light scratches in the cylinder bores - Light scratches are ones that you have to run your nail over a few times to decide if it really is a scratch put the new rings in, they will seal up and the engine will operate OK. Deep gouges in the block and the engine must be replaced. |
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Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed. If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance. This diagnostic approach was developed for the vehicle with the VIN you entered and should not be automatically be used for other vehicles with similar symptoms.
Models:
(2000 CADILLAC DEVILLE 4.6L (LD8) ENGINE) and (2001 CADILLAC DEVILLE 4.6L (LD8) ENGINE) and (2002 CADILLAC DEVILLE 4.6L (LD8) ENGINE) and (2003 CADILLAC DEVILLE 4.6L (LD8) ENGINE) and (2000 CADILLAC ELDORADO 4.6L (LD8, L37) ENGINE) and (2001 CADILLAC ELDORADO 4.6L (LD8, L37) ENGINE) and (2002 CADILLAC ELDORADO 4.6L (LD8, L37) ENGINE) and (2000 CADILLAC SEVILLE 4.6L (LD8, L37) ENGINE) and (2001 CADILLAC SEVILLE 4.6L (LD8, L37) ENGINE) and (2002 CADILLAC SEVILLE 4.6L (LD8, L37) ENGINE) and (2003 CADILLAC SEVILLE 4.6L (LD8, L37) ENGINE)
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