Starter Motor on my Jeep made a loud Clunking Noise

Suspected starter motor

A few week ago now, a guy came into my garage and asked us to fit him a new battery. We always test the old battery, unless the customer tells us the old one is completely dead. This guy Starter Motorhad a Jeep and we said that the battery had been slow to start the car for about a month now and he thought that it was going to let him down completely. He worked in Manchester about 30 mile away from Halifax here in Yorkshire and so did not want to risk expensive breakdown chargers. We fitted a new battery and the guy went away happy. After about a month the guy turned back up again.

He said that the problem appeared to be cured after the new car battery was fitted, but recently he had started to hear a low level clunking noise coming from the engine when he started the car. He said that it was the old problem that was occurring and could the battery be faulty?

This also happens with a faulty alternator. The first thing that the customer does is to buy a new battery, then a few weeks later , the car still has starting problems because the alternator has been under-charging or over-charging. Eventually the car has to have a replacement alternator. It is the same with the starter motor, although the starter is not as common a fault as the alternator, at least not here in Halifax.

Our top mechanic Ryan went out to check the car out and found the clunk was indeed coming from the starter motor when starting the car. There are a few things that you need to know

about diagnosing this problem. The main one is when you try to start the car, (and this applies to all cars and vans, in fact any vehicle that is fitted with a starter motor, will have similar symptoms) you turn the key to turn the engine over, but nothing happens, the engine will turn over. This is what would have eventually happened to the Jeep.

Also when you try to turn over the engine you hear a loud click. In this case the car’s engine will still not turn over. This scenario is also the same as a dead flat battery, but I am presuming that the cars have had a new one fitted, prior to the starter clicking again. This can go on for a little while and sometimes the car will eventually start. The starter engages with the vehicles flywheel and turns over the engine until the car starts, and sometimes it is the starters gear teeth that are broken. But if you are lucky enough the hit the starter key at the right time, then the car may just start.

Back in the olden days cars with inline engines would have a cranking handle. So that you could turn over the engine, by hand (if you were strong enough). However cars started to come out with front wheel drive engines and the cranking handle became obsolete.

Our Jeep needed a new starter motor

Ryan very quickly diagnosed that the starter motor needed replacing, and after giving the gut a price for the job, Ryan began the difficult job of removing the old motor. Years ago the starters were easy to find and replace, but the advent of the computer designed cars, the manufacturers can squeeze parts onto an engine where

jeep, starter motor, and battery

New and old Jeep starters side by side

they previously could not. This Jeep was no exception and the starter was tucked away in nowhere land and very difficult to remove, right up the back of the engine, certainly not a job for the DIY car repairer, on his back on the drive at home.

The new part arrived and was fitted back in the engine by Ryan. The problem was that the teeth on the old motor were worn away, and were not connecting with the flywheel. Sometimes we find that there is an electrical fault, but not in this case. The old starter was sent back to the supplier and then returned to the company that will recondition the starter to repeat the cycle again when the next Jeep start motor goes wrong.

We normally carry out the following tests to ascertain whether or not a new starter motor  is required.

A- We always test the battery first. This is by using a simple multi-meter test.

B- We will check that the starter motor is getting 12 Volts on to its Battery Circuit.

C- We always check that the starter motor is receiving the electrical current from the ignition switch.

D- We carry out a voltage drop test on the starter battery and ground Circuits. We do this using a 12 volt battery and a connecting wire to test whether or not the starter is engaging or not. We test this in a vice on the bench.

Pellon Tyre and Auto-centre offer car and van servicing and repairs to all makes of vehicles. We are members of Unipart Car Care centres and give a nationwide guarantee for all our work and parts. We also sell Jeep Tyres Online from our website www.pellontyres.co.uk by using the tyre selector and choosing your tyre size. We offer courtesy cars to local motorists who need to go to work and leave their car with us for work doing. We are also an official MOT testing station and are members of Motor-codes, who carry out checks for high standard of equipment and workmanship.