Timing chain diagram 4.6 northstar engine - 1999 Cadillac DeVille

You must firs diagnose the failure, fuel or ignition..

Try starting on test fuel sprayed in any unmetered vacuum nipple...

... Philip

I need to know what year Grand Am and engine size?

I noticed your question was not answered yet, so I am trying to help. I watched another mechanic perform a teardown on one of these big Northstar engines in a DTS model.

In his case, he wanted to pull the heads. Now in the process he had to remove all of the timing chains. His engine was a 4 cam, meaning there are 4 Timing chains on the motor.

The access to the Timing chains was poor. I believe you would still have to drop the motor "Cradle" to be able to remove the crankshaft damper and the front Timing chain cover. There are sprockets on the Cams which require taking out plastic access plugs in the cylinder heads to get at the Timing chain tensioners.

Depending on whether the new chain has an "open" link or if it is a continuous loop will determine if you need to remove the other Timing chains that are in front of the position of your bad chain. If the bad chain is the outermost chain, then you just remove the first chain and replace it. But if it is the last chain, you need to get to it by removing the chains in front of it.

I can tell you that the Northstars require a periodic cylinder combustion chamber cleansing with a special additive(usually annually). This additive is available at the Dealer and once you know the exact chemical, you may try to get it at an autoparts supplier if it is not a proprietary product. There is an installation process.

This product requires the engine to rest with the additive installed at least 8 hours and preferably 24 hours. It will decarbon the heads. I say this to you because unless you know for sure that a Timing chain is bad, your valves may simply be carbon fouled. I understand it can be common in Northstar engines. They are built like a race engine, but require more service.

Using this chemical could easily save you $3000 or more in motor work, and if the problem was not the carbon, it should have been done as part of regular maintainance anyway. Then go ahead with the Timing chain replacement if the chemical does not help.

Now it does pay to check around for prices. "If" you have to have the "cradle" pulled, it will be very expensive. Basically the body and the engine/transmission are separated if that gives you some idea of how drastic and time consuming this repair can be.

There are always new tools coming to market to bypass some of the obstacles in repairs. Someone may know a new trick to saving labor.

I would like to know the outcome of your situation.

The 1995 Oldsmobile Aurora with the Northstar engine has a timing chain.

Yes, it is possible. Most probable cause is a timing chain guide that is broken or the hydraulic chain tensioner is bad. No way to tell without going into engine. Unfortunately Northstars are not fun for the novice, or even slightly motivated weekend mechanic to tackle.

You have the tensioner out right? Is the engine still in the car or do you have it out?

The northstar engine uses chain driven cams that eliminates the need to replace timing belts.
Thank you and enjoy,
Lee

need 1998 northstar engine diagram to change the head gasket thanks

Setting the camshaft timing isnecessary whenever the camshaft drive system has been disturbed,meaning the relationship between any chain and sprocket has been lost.Correct timing exists when the crankshaft and intermediate shaftsprocket timing marks are in alignment and all 4 camshaft drive pinsare perpendicular (90 degrees) to the cylinder head surface.

degrees) to the cylinder head surface. I hope this helps, if not let me know

rate me FIXYA!....thanks!