Quite a few things can cause the engine to 'crank but not start' on your 3.8L V6 Chrysler (Dodge, Plymouth) minivan.
In the majority of cases, the no-start problem usually boils down to one of the following:
- An ignition system problem.
- A bad fuel pump.
- An engine compression problem.
- A blown head gasket.
Testing a 'cranks but does not start' problem is not a difficult thing to do, and believe it or not, there is a method to the madness.
In this tutorial I'm going to describe the process that I follow to be able to diagnose a 'cranks but does not start' problem.
The diagnostic process I'm about to describe is going to help you to get to the bottom of the problem that's causing your mini-van's engine to 'crank but not start'.
Contents of this tutorial:
- Difference Between A No Start And A No Crank Condition.
- No Start Condition Basics.
- What Tools Do I Need?
- STEP 1: Testing The Ignition System For Spark.
- STEP 2: Testing The Fuel Pump's Pressure.
- STEP 3: Making Sure The Engine Has Good Compression.
- STEP 4: Checking For A Blown Head Gasket.
- No Start Troubleshooting Summary.
- Where To Buy An HEI Spark Tester And A Fuel Pressure Gauge.
You can find this tutorial in Spanish here: Cómo Diagnosticar Un Arranca Pero No Prende (3.8L V6 Chrysler, Dodge, Plymouth Mini-Van) (at: autotecnico-online.com).
APPLIES TO: This tutorial applies to the following vehicles:
- 3.8L V6 Chrysler Town & Country: 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010.
- 3.8L V6 Dodge Grand Caravan: 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010.
- 3.8L V6 Plymouth Voyager: 1994, 1995, 1996.
- 3.8L V6 Plymouth Grand Voyager: 1994, 1995, 1996, 1997, 1999.
Difference Between A No Start And A No Crank Condition
Before we get going, it's important to note that this tutorial will only help you to diagnose a cranks but does not start problem.
In a 'cranks but does not start' problem, the starter motor will engage and crank the engine but the engine will not start.
For the most part, the engine will not start because it's either not getting fuel, or it's not getting spark, or it's not getting air (like in an engine compression problem).
In a no crank condition, the starter does not crank the engine. This is usually due to the fact that the starter motor is bad, or the engine has seized, or something is preventing the starter motor from engaging the engine (like a bad ignition switch).
So, if in your case, the starter motor is not cranking the engine, then this tutorial will not help you. The following tutorial will help you test the starter motor: How To Test The Starter Motor On the Car (Step by Step).
No Start Condition Basics
As I mentioned earlier, what will usually keep the engine from starting 1 of 3 things:
- The engine is not getting fuel.
- The engine is not getting spark.
- The engine has cylinder compression problems.
This boils down to doing 3 basic tests to get to the bottom of the no start problem. We need to:
Test The Ignition System: We need to make sure that each cylinder is getting spark with a spark tester.
Usually a bad crankshaft position sensor or a bad camshaft position sensor is the behind the engine's 6 cylinders not getting spark.
Test The Fuel System: We need to make sure that the fuel pump is working and supplying the correct amount of fuel pressure. This is accomplished by doing a fuel pump pressure test.
A bad fuel pump is usually behind the engine not getting fuel.
Test Engine Compression: We need to make sure that each cylinder has a normal compression value.
An engine compression problem, that's causing the engine not to start, is usually caused by a serious internal engine problem (like a thrown rod or busted timing chain).
Test For A Blown Head Gasket: A blown head gasket is usually the result of severe engine overheating and can cause the engine to 'crank but not start'.
In the following pages you'll find a basic testing guide so that you can find out what's behind your mini-van's no start problem.
What Tools Do I Need?
To find out what's behind your mini-van's not start problem, you're gonna' need a few specialized tools. Don't worry, these tools will not break the bank and most of them you can borrow (for a deposit) from your local auto parts store.
Here's a basic list of what you'll need:
- Spark tester.
- Noid light set.
- Fuel pressure tester.
- Engine compression tester.
For the spark tests of the ignition system, I'm gonna' suggest that you use an HEI Spark Tester.
This tester is the most accurate tester on the market and isn't expensive. You can find out more about it (and where to buy it) here: HEI Spark Tester. Or you can take a look at this section: Where To Buy An HEI Spark Tester And A Fuel Pressure Gauge.
You'll notice that I didn't include a scan tool in the list. But if you have one, I can tell you that it'll come in handy. Why? Because some of the components that cause a no start condition can leave a specific trouble code (when they fail).
In this tutorial I haven't included it (a scan tool) in any of the suggested tests because they can be done without one.
Let's turn the page and get testing.