MajorCommonEngine

RAM 1500: Intake plenum pan gasket leak causing oil burning (2nd gen and early 3rd gen, 5.2 and 5.9 Magnum V8)

Intake plenum pan gasket leak causing oil burning (2nd gen and early 3rd gen, 5.2 and 5.9 Magnum V8) is a common engine fault on the RAM 1500 on the 1994–2003 cars, and we rate it major. Putting it right costs $600 to $1,500 at New Zealand independent workshop rates. Below is what goes wrong, the symptoms to notice on a test drive, where to look, and what to ask the seller before you hand over any money. It is one of 22 documented faults on the RAM 1500.

Vehicle: RAM 1500
Engine: 5.2L / 5.9L
Years: 1994–2003
Fuel: petrol
System: Engine

This page covers the RAM 1500 as a model. Some faults only affect particular engines or build years — enter a plate below to narrow the list to one car.

All RAM 1500 faults22 documented faults on this model

What you are looking at

No photograph available

We do not hold a verified photograph of the Catalytic converter or Intake manifold yet. We would rather show none than show a picture of a different part.

What goes wrong

The 5.2 and 5.9 Magnum V8 intake manifold is an aluminium casting with a stamped steel plate bolted underneath, sealed by a plenum gasket. The two metals expand at different rates, and after years of heat cycling the gasket tears. Manifold vacuum then sucks crankcase oil mist into the intake runners, so the engine burns oil (often worst on one rear cylinder), smokes, fouls plugs, pings under load and can idle rough or set lean codes. Left alone it carbons up the oxygen sensors and plugs, and the oil burning can damage the catalytic converters. There was no recall; the fix is a revised bolted plenum repair kit and a new gasket, plus a front oxygen sensor if it is fouled. The 3.9 V6 shares the same design. The 5.9 Magnum carried on in the 2002 and 2003 DR Ram 1500.

What you would notice

Oil level drops between services with no visible leak
Blue smoke from the exhaust, especially after idling or on acceleration
Pinging or knocking when accelerating uphill or towing
Rough idle or a misfire, often on one rear cylinder
Oily, fouled spark plugs

How to check it

Where to look. Underside of the intake manifold in the valley of the V8, beneath the throttle body

Check the dipstick level and ask how much oil the truck uses between services.
Start the engine and have a helper watch the tailpipe while you rev it after it has idled for a minute, looking for a puff of blue smoke.
Listen for pinging or rattling on a firm uphill acceleration during the test drive.
Look for fresh oily residue at the tailpipe outlet.
Ask whether the plenum gasket or intake plenum plate has ever been replaced, and ask to see receipts.
If a workshop inspection is possible: remove the throttle body or PCV hose to look for pooled oil in the intake, read the spark plugs for oil fouling, and scan for misfire and lean codes.

Parts involved: Catalytic converter, Intake manifold.

What it costs to put right

$600 to $1,500 at New Zealand independent workshop rates. That is for this job on its own, not for the car.

An estimate, in NZD, for the repair as normally carried out. What a specific car costs depends on which part has failed and what it damaged on the way — treat this as the floor for a negotiation, not a quote.

Ask the seller

“How much oil does it use between services?”
“Has the intake plenum gasket or plenum plate ever been replaced?”
“Has it ever had an oil-fouled plug or misfire fault?”

Now check the RAM 1500 you are actually looking at

Everything above is true of the model, and it is free. What it does not tell you is whether THIS car has been looked after: its odometer history and whether the reading has ever gone backwards, whether there is still money owing on it, whether it has been reported stolen, how many owners it has had and what it is really worth today. That comes from the official records for that plate. Enter the plate for the free details, or get the full history and a market valuation from $13.49.

Not sure what you would be paying for? See what a full KickTyres check includes.

Where this comes from

The failure described above is documented in the sources below. The inspection instructions and the cost estimate are KickTyres’ own interpretation of them.

UnderhoodService: Tech Tip, Servicing 1993-2003 3.9/5.2/5.9L Dodge Magnum Engines (plenum cover gasket leak draws oil into the intake, oil usage, smoking, pinging, fouled O2 sensor)
8020 Automotive: The 5 Most Common Dodge 5.9 Magnum Engine Problems (plenum gasket leak, 1992-2003)
BobIsTheOilGuy forum thread: 5.9 Dodge Magnum oil advice

RAM 1500 buyer questions

Is intake plenum pan gasket leak causing oil burning (2nd gen and early 3rd gen, 5.2 and 5.9 magnum v8) serious on a RAM 1500?

We rate it major and common on the RAM 1500. The 5.2 and 5.9 Magnum V8 intake manifold is an aluminium casting with a stamped steel plate bolted underneath, sealed by a plenum gasket. The two metals expand at different rates, and after years of heat cycling the gasket tears. Manifold vacuum then sucks crankcase oil mist into the intake runners, so the engine burns oil (often worst on one rear cylinder), smokes, fouls plugs, pings under load and can idle rough or set lean codes. Left alone it carbons up the oxygen sensors and plugs, and the oil burning can damage the catalytic converters. There was no recall; the fix is a revised bolted plenum repair kit and a new gasket, plus a front oxygen sensor if it is fouled. The 3.9 V6 shares the same design. The 5.9 Magnum carried on in the 2002 and 2003 DR Ram 1500.

How much does it cost to fix on a RAM 1500?

$600 to $1,500 at New Zealand independent workshop rates. That figure is for this job on its own. A car showing the symptoms on this page is usually worth either walking away from or negotiating down by at least the repair figure.

Which RAM 1500 years are affected?

Our research records this fault on the 1994–2003 RAM 1500. Build dates move around, especially on imported cars, so treat the range as the years to look hardest at rather than a guarantee either way. The official records tell you the exact build and first registration date for the car in front of you.

How do I check for it before I buy?

Check the dipstick level and ask how much oil the truck uses between services. Start the engine and have a helper watch the tailpipe while you rev it after it has idled for a minute, looking for a puff of blue smoke. Listen for pinging or rattling on a firm uphill acceleration during the test drive. Look for fresh oily residue at the tailpipe outlet. Ask whether the plenum gasket or intake plenum plate has ever been replaced, and ask to see receipts. If a workshop inspection is possible: remove the throttle body or PCV hose to look for pooled oil in the intake, read the spark plugs for oil fouling, and scan for misfire and lean codes. Look here: Underside of the intake manifold in the valley of the V8, beneath the throttle body