Common 3800 Series 2 Problems

The 3800 series 2 is a reliable engine, but coolant leaks on the Series II 3800 engines with the plastic intake manifold have been a problem intake manifold coolant leaks on the Series II engines. The Cracks can allow coolant to seep into the cylinders, causing the engine to hydro lock in some cases. Don’t worry this article discusses 3800 series 2 problems. So, read until the end.

What Is The 3800 Series 2 Engine?

The GM 3800 Series II engine, was introduced in 1995,  which differs significantly from its predecessor, the Series I engine. While the 3.8L engine’s stroke remained 3.4″ (86 mm) and bore remained 3.8″ (97 mm), the engine architecture changed dramatically.

The deck height is lower than that of the Series I, reducing weight and total engine package size. To make this change, GM engineers needed to shorten the piston connecting rods by 1″ (25 mm) and redesign the crankshaft.

A redesigned cylinder head featured bigger valves and a higher compression ratio, while a new intake manifold improved breathing.

Common 3800 Series 2 Problems

1. Engine Cracking Without Starting

The most common in the Buick-3800 engine is faulty CKP sensors and ICM while there can be a variety of causes for no start. Here, in this case, CKP stands for the crankshaft position, and ICM stands for the ignition control module.

To begin, the CK or crank sensor can be diagnosed by inspecting the engine wiring diagram in your vehicle. To find the fault, you must first test the voltages of the circuits for the ignition module and many crank sensors. Furthermore, when you turn the key on, 4-8 volts it must be found between each crank sensor. If it fails the tests, replace the crank sensors.

2. Intermittent Misfire While Driving

Intermittent misfire happens while driving due to a worn spark plug or a weak coil. When an intermittent misfire occurs while driving, the first thing to do is remove the spark plugs and inspect them carefully. There must be a 0.60-inch gap between these spark plugs. If your spark plug is acceptable, leave it alone and proceed further to inspect the ignition wires.

However, After replacing the damaged wires and plugs then also your engine continues to behave in the same manner then, use a scanning tool to look for misfire codes. Moreover, keep the check engine light on and ensure you get 1-2 misfire codes for the cylinders causing misfires.

You can easily replace the weak coil in the ignition module. Don’t leave any of the bad coils remained unattained because then the problem will not resolve. You should replace all of the coils if your engine is high mileage or weak, to avoid such problems on road.

3. If The Coolant In The Intake Manifold Is Leaking

Coolant leaks in Buick-3800 engines, particularly in Series II 3800 engines. Similarly, here the massive plastic consumption has caused problems for people.

If it is running in an area where the cylinder head gets sealed coolant passage due to the manifold. After 60,000 miles the OEM gasket manifold intake tends to weaken.

4. Intermittent Hesitancy Or Chugging

You may notice an intermittent hesitation or struggle during highway cruising or light acceleration. It occurs when the automatic TCC’s (transmission torque converter) intermittent operations do not set fault codes or when the check engine light does not illuminate.

5. Engine Cracking Without Start

There can be many reasons that lead to no start, however. The most generalized reason for Buick is the bad CKP sensors and ICM. Where CKP means crankshaft position and ICM means ignition control module.

Firstly, the CK or crank sensor can be diagnosed by evaluating the diagram of your vehicle’s engine ring. Secondly, you need to test the voltages of circuits for the ignition module and many crank sensors to search for the fault. Moreover, 4-8 volts must find when you turn the key on between every crank sensor. If it tests badly replace these crank sensors.

Why Did Disc Discontinue The Production Of The 3800?

After only two years disc discontinue the production of the 3800 because GM couldn’t get consistent quality from the difficult-to-cast aluminum blocks,  and that’s the reason the engine was discontinued after only two years. However, the basic design and technology were revived for an iron block, a 198-cubic-inch V6 engine.


The above article discusses the 3800 series 2 problems. Practicing the above-mentioned diagnostics will help you in resolving the problems. If you have any queries with the mentioned information then please comment below we will get back to you as soon as possible.


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